This creamy dish of potatoes Diane is made with thinly sliced potatoes, layered with caramelised onions and mushrooms, then oven-baked in a rich brandy, mustard and cream sauce. Finished with a golden, melty cheese topping, this is the perfect side dish for a roast, for sausages, or hearty enough to enjoy as a vegetarian main.
What is/are potatoes Diane?
Potatoes Diane is really just a potato bake, but it's more than that. It's actually a combination of several of my recipes:
- Cheesy bacon and onion potato bake (without the bacon)
- Boulangere potatoes (which are also cooked in stock)
- Chicken Diane (for the creamy brandy sauce)
To be honest, that's what cooking is all about - taking the best parts from various recipes and combining them to come up with something completely different. Well, that's my theory anyway 😋. And who wants to eat the same food night after night, when with a bit of imagination and ingenuity, you can eat something different every night of the week?
That's how this potato and mushroom bake recipe came about. I've been making it for years, and it always gets rave reviews! It's the sort of dish that takes hardly any time at all to prepare, then it goes into the oven, and you can forget about it until you're ready to eat!
Back in the day, this cheesy potato bake always made an appearance at one of the frequent braais (or barbeques) - the creamy, almost fondant-like potatoes making a delicious change from the ubiquitous potato salad. And my family devoured it whenever I served it alongside a roast instead of roast potatoes.
Let's see how to make it!
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Recipe at a glance
- Quick overview of potatoes Diane: Layers of thinly-sliced potatoes are arranged with caramelised onions and mushrooms in a baking dish and covered with stock and flavourings. It's baked in a covered dish for 75 minutes until the potatoes are tender. Grated cheese can be optionally added and browned (uncovered) for the final 15 minutes.
- Main ingredients: Potatoes, onions, mushrooms, cheese, cream, stock, brandy.
- Prep time: Prep time - 25 minutes - you need to peel/clean and slice a few potatoes, onions and mushrooms, saute the onions and mushrooms, layer everything in a baking dish and cover it with the sauce ingredients.
- Cooking time: Cooking time - 75 minutes. It seems like a long time, but you want to give the potatoes time to soften and soak up all the lovely creamy stock.
- Yield: Serves 6 to 8 people, depending on appetite.
Why you'll LOVE it
- Well, firstly, it's a potato bake, and I haven't found anyone yet who doesn't love a creamy potato bake!
- The potatoes soak up the most amazing flavours as they cook - cream and brandy, sweet tomato, savoury Worcestershire sauce, tangy mustard, tasty chicken stock ... I'm salivating at the thought!
- Easy prep, then into the oven. There's not much prep involved - the oven does most of the work.
- Incredibly versatile - serve it with a roast or sausages, or let it shine as an easy vegetarian main with a crisp salad (perhaps add a few extra mushrooms)!
Ingredients for potatoes Diane
**You can find the exact ingredient quantities on the printable recipe card at the end of this post.**
- Potatoes. You want a good all-rounder potato - not too floury; a potato that will hold its shape, but soften nicely as it soaks up all the flavours. You could use Maris Piper or King Edward in the UK, or one of the red-skinned varieties such as Desiree or Rooster. In the US, you could use Russet or Yukon Gold, and in Australia, Sebago. The potatoes should be peeled and thinly sliced. A mandolin makes short work of this, or you could practice your knife skills with a sharp knife and a little patience.
- Onions. White onions (or brown or yellow) are best, but you could get away with using red onions if those are all you have. They should also be peeled and thinly sliced.
- Mushrooms. Wipe the mushrooms with a damp cloth to remove any bits of dirt and slice them thinly. You can use either white closed-cap or chestnut (cremini) mushrooms. I find that the larger Portobello mushrooms contain too much liquid, so I tend not to use those for this dish.
- Butter. This is used to soften the onions and mushrooms, and it adds a whole lot of flavour to the sauce. Substitute with any neutral-flavoured vegetable oil.
- Cheddar cheese. This got left out of the photo (oops). You will need some grated cheese to sprinkle over the top of the potato bake for the final 15 minutes in the oven.
Diane sauce
- Chicken stock. You can make the stock with a stock cube or use fresh stock. If you don't have chicken stock (or a chicken stock cube), substitute with vegetable stock. I would not use beef stock as the beefy flavour would be too strong.
- Cream. I like to use double or heavy cream, but single or pouring cream will work too.
- Brandy. You can use any brandy - it doesn't have to be expensive cognac - house-brand is fine. Substitute with marsala or dry sherry. If you don't want to cook with alcohol, you could buy a bottle of brandy essence (available on Amazon) or add a tablespoon of balsamic vinegar instead.
- Dijon mustard. Adds warmth. I've specified 1 to 2 teaspoons in the recipe - you can decide for yourself how much you want to add depending on your taste.
- Worcestershire sauce. Provides a salty element.
- Tomato puree (or tomato paste). Adds a little sweetness and rounds out the flavour of the sauce.
- Salt and black pepper. For seasoning.
💡Tip - The chicken stock and Worcestershire sauce may add sufficient seasoning. Combine all the sauce ingredients in a jug and taste before adding salt and pepper.
How to make this easy potato bake
Preparation
- Peel the potatoes and slice them thinly (approximately ⅛ inch) using a mandolin. Try to keep all the slices the same thickness.
- Peel the onion and slice thinly.
- Wipe the mushrooms with a damp cloth to remove any bits of dirt and slice them thinly. Never submerge mushrooms in water - they are like little sponges and will absorb water, which will be released into your dish.
Step 1: Melt the butter over moderate heat in a frying pan and add the onions. Fry for 3 to 4 minutes, stirring continuously until they soften and start to change colour.
Step 2: Add the mushrooms and stir for a further 2 to 3 minutes.
💡Tip - Don't allow the onions to become too brown. The aim is to get them soft and translucent. They will continue to cook in the oven with the potatoes.
Step 3: Place an overlapping layer of potatoes (similar to fish scales) on the bottom of a casserole dish and top with half of the mushroom and onion mixture.
Step 4: Top with a layer of potatoes, the remaining mushrooms and onions and a final layer of potatoes (3 layers of potatoes in total).
💡Tip - Keep your best-looking potato slices for the top of the potato bake - makes for nicer presentation when you put the dish on the table.
Step 5: Combine the sauce ingredients in a jug. Taste for seasoning and add salt and pepper as necessary.
Step 6: Pour the sauce evenly over the potatoes, mushrooms and onions.
💡Tip - You'll need about 1½ cups of stock - just enough to come roughly halfway up the dish. Be careful not to add too much, as any excess won't fully absorb and could leave the finished bake a little watery.
Step 7: Cover with tin foil (or lid if your dish has one) and bake for one hour at 190C / 380F.
Step 8: Remove the dish from the oven and discard the tin foil. Sprinkle with grated cheese and return the dish to the oven.
💡Tip - Adding grated cheese to the dish is optional, but I do recommend you cook the dish uncovered for the final 15 minutes. Even without adding cheese, you'll still want the potatoes to be nice and brown.
Step 9: Bake uncovered for a further 15 minutes until the cheese is melted and golden.
Serving suggestions
- Serve alongside a roast as an alternative to roast potatoes.
- Add extra mushrooms and serve it with a salad as a light vegetarian meal.
- Add it to your barbeque sides table.
- Serve it as a side dish with crispy Korean chicken wings or sticky honey lemon chicken wings.
Variations
If you would like to alter the recipe to suit your taste, here are a few ideas:
- Garlic and parmesan. Fry a few crushed garlic cloves with the onions and swap out the cheddar cheese for parmesan.
- Bacon. For a heartier dish that could double up as a light supper, add a few slices of crispy bacon between the potato layers.
- More crunch. Combine the grated cheese with either breadcrumbs or crushed potato crisps for a crispier topping.
Equipment
These are the main items of equipment you will need:
- I used an enamel baking dish 10" x 8" (25 cm x 20 cm) and 2" (5 cm) deep. You need the dish to be deep enough to hold the potatoes with enough room for the stock, without the dish becoming too full. If the dish is completely filled, you will find some of the liquid will overflow as it bakes. I tend to put my dish onto a flat baking sheet to catch any spills.
- A mandolin will make short work of slicing the potatoes and onions, or just use a sharp knife.
- For softening the mushrooms and onions, you will need a frying pan or saucepan.
- You will also need a container to mix the sauce. I used my measuring jug.
Storing and freezing
- Refrigerator. Leftover potatoes can be stored in a covered container in the refrigerator for 3 to 4 days.
- Freezing. You can also freeze leftovers for up to 2 months. Let them defrost in the refrigerator before reheating.
- Reheating. You can either reheat the potatoes in a covered container in the oven or reheat them for a few minutes in the microwave.
- Meal prep. ~This recipe is ideal for meal prep. I would recommend assembling the dish in disposable aluminium containers. Leave off the cheese topping and only add it when baking. Freeze unbaked for up to 3 months. Bake from frozen, at a slightly lower temperature, for about 15 minutes longer than the time given in the recipe.
💡Top tip
There is nothing worse than under-cooked potatoes! Test that the potatoes are cooked by poking them with a skewer or a sharp knife. The knife should slide in with no resistance. If the potatoes feel too firm, leave the dish in the oven for a few minutes longer.
FAQ
Potatoes Diane is naturally gluten-free, but you should check your Worcestershire sauce and stock to ensure they are certified gluten-free.
Yes, use vegetable stock, and ensure your Worcestershire sauce is certified as suitable for vegetarians.
Yes, assemble the dish up to 24 hours in advance, cover and refrigerate, and bake it when you are ready.
This usually means the potatoes were sliced too thickly, or the foil was removed from the dish too soon. Cover the dish and bake for a few minutes longer.
Save for later
If you would like to make this easy potato bake, why not save the recipe to one of your Pinterest boards so you can find it easily? Just click the image below.
Alternatively, you can save the recipe by clicking on the floating heart icon on the right-hand side of the screen.
Related recipes
Visit my vegetable recipes page for other tasty side dishes. Here are a few that use potatoes that you might like to try:
📋The recipe
Potatoes Diane - a one dish potato bake
(Click the stars to rate this recipe)
Equipment
- Baking dish 10" x 8" or 25 cm x 20 cm
- Mandolin OR
- Sharp Knife
- Frying Pan
- Small jug or bowl
Ingredients
Vegetables
- 1½ pounds / 680 grams potatoes peeled and sliced to ⅛-inch
- 2 medium onions peeled and sliced
- 8 ounces / 225 grams mushrooms wiped and sliced
- 1 ounce / 30 grams butter
- ¾ cup / 90 grams grated cheddar cheese
Sauce
- 1 cup / 240 ml chicken or vegetable stock you can make it with a stock cube
- ½ cup / 120 ml double or heavy cream
- 1 - 2 teaspoons Dijon mustard depending on your own taste
- 1 tablespoon tomato puree or tomato paste
- 1 tablespoon Worcestershire sauce
- 2 tablespoons / 30 ml brandy
- Salt to taste optional
- Black pepper to taste optional
Instructions
- Melt the butter over moderate heat in a frying pan and add the sliced onions. Fry for 3 to 4 minutes, stirring continuously until they soften and start to change colour.1 ounce / 30 grams butter, 2 medium onions
- Add the sliced mushrooms and stir for a further 2 to 3 minutes.8 ounces / 225 grams mushrooms
- Place an overlapping layer of sliced potatoes (similar to fish scales) on the bottom of a casserole dish and top with half of the mushroom and onion mixture.1½ pounds / 680 grams potatoes
- Top with a second layer of potatoes, the remaining mushrooms and onions and a final layer of potatoes (3 layers of potatoes in total).
- Combine the sauce ingredients (except the salt and pepper) in a jug. Taste for seasoning and add salt and pepper as necessary.1 cup / 240 ml chicken or vegetable stock, ½ cup / 120 ml double or heavy cream, 1 - 2 teaspoons Dijon mustard, 1 tablespoon tomato puree or tomato paste, 1 tablespoon Worcestershire sauce, 2 tablespoons / 30 ml brandy, Salt to taste, Black pepper to taste
- Pour the sauce evenly over the potatoes, mushrooms and onions. It should come halfway up the dish, or almost to the top of the potatoes.
- Cover with tin foil (or lid if your dish has one) and bake for one hour at 190°C / 180°C (fan) / 375°F.
- Remove the dish from the oven and discard the tin foil. Sprinkle with grated cheese and return the dish to the oven.¾ cup / 90 grams grated cheddar cheese
- Bake uncovered for a further 15 minutes until the cheese is melted and golden.
Notes
- Don't overcook the onions - they will continue to cook once the dish goes into the oven. The aim is just to soften them slightly.
- Keep the best-looking potato slices for the top layer - they will help form a nicer-looking presentation!
- Don't add seasoning to the stock until you've tasted it. The chicken stock and Worcestershire sauce may add sufficient seasoning. Combine all the sauce ingredients in a jug and taste before adding salt and pepper.
- You'll need about 1½ cups of stock - just enough to come roughly halfway up the dish. Be careful not to add too much, as any excess won't fully absorb and could leave the finished bake a little watery.
- Adding grated cheese to the dish is optional, but I do recommend you cook the dish uncovered for the final 15 minutes. Even without adding cheese, you'll still want the potatoes to be nice and brown.
- There is nothing worse than under-cooked potatoes! Test that the potatoes are cooked by poking them with a skewer or a sharp knife. The knife should slide in with no resistance. If the potatoes feel too firm, leave the dish in the oven for a few minutes longer.
Nutrition
I am not a nutritionist. The nutrition information has been calculated using an on-line calculator, and is intended for information and guidance purposes only. If the nutrition information is important to you, you should consider calculating it yourself, using your preferred tool.
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