French onion potato bake

This easy French onion potato bake is made with thinly sliced potatoes and onions, layered with homemade French onion soup mix and cream, then topped with grated cheese and baked until the potatoes are tender and the top is golden and bubbling. This is a flavour-packed side dish that goes perfectly with roast meat, chicken, fish or sausages.

Back in the day, a packet of French onion soup in the pantry always guaranteed a tasty meal. I used it to make this tasty potato bake, but I also used it in my French onion beef pasta bake and this French onion chicken casserole.

Unfortunately, dehydrated French onion soup mix has become increasingly difficult to find in UK supermarkets, and for a long time this was one of those recipes that simply disappeared from my regular meal rotation. Now that I've developed my own homemade French onion seasoning mix, I can finally make it again.

And I'm very glad I did! This is one of those old-fashioned side dishes that doesn't need anything fancy to make it good. The French onion seasoning provides plenty of savoury flavour, while the cream keeps the potatoes moist as they cook, and the cheese adds a lovely golden topping.

It's also extremely easy to prepare. There's no need to parboil the potatoes or make a separate sauce; everything goes into the baking dish, and the oven does the rest. The only thing to bear in mind is that the potatoes should be sliced quite thinly and evenly so they cook through at the same time.

I've used my homemade French onion seasoning mix here, but if you live somewhere that still sells packets of dehydrated French onion soup, you can use that instead. Either way, I'm rather pleased to have this old favourite back on the menu.

Why I love this French onion potato bake

• Easy to make. There's no need to parboil the potatoes or make a separate sauce. Simply layer everything into the baking dish, pour over the cream and let the oven do the work.
• Full of flavour. The French onion seasoning mix adds plenty of savoury onion flavour, while the cream and melted cheese turn the potatoes into something a little more special than an everyday potato side dish.
• It goes with most things. Serve it alongside roast or grilled meat, with chicken, sausages or fish. Add a green vegetable or salad and you've got an easy meal.
• Easy to prepare ahead. Assemble the potato bake in advance and keep it in the refrigerator until you are ready to put it in the oven - handy if you're cooking for the family or entertaining.
• It's an old favourite I can make again. I really missed my French onion potato bake! Now that I've got my homemade French onion seasoning mix, I can make it whenever I feel like it!

Ingredients for French onion potato bake

**This is just an overview to explain why I used a particular ingredient. The complete list of ingredients and the exact measurements are on the printable recipe card at the end of this post.**

• Sliced potatoes. I used Maris Piper potatoes because they hold their shape and don't turn mushy in the potato bake. You can use any nice, firm potato. They should be thinly sliced - I used a mandolin and sliced them to one-eighth of an inch thick You could use a sharp knife instead, but try to get them all cut to an even thickness so they cook at the same time..
• Onions. I used a white onion and sliced it to the same thickness as the potatoes. This potato bake has 3 layers: potatoes, onions, and a final layer of potatoes. So you will need just enough onions to go in the middle. I found one medium onion was sufficient, but of course, if you want more onions, by all means use a large onion instead!
• French onion seasoning mix. This is my homemade seasoning mix, which I concocted because I can't find dehydrated French onion soup mix in the shops. I make it in bulk and store it in a screw-top jar in the cupboard so it's always at hand. You can substitute with dried French onion soup if you can find it. If you don't want to make a full batch of my seasoning mix, see the next section below for a small batch that makes just enough for this potato bake.
• Cream. I like to use a mixture of double (or heavy) cream and milk, but you could use single cream instead. If you're watching calories, you might want to substitute the cream with milk, but do use full-fat rather than semi-skimmed.
• Grated cheese. This is optional, but good! Sprinkle it over the potato bake before it goes into the oven. I use a mixture of cheddar and mozzarella, but you can use any cheese that you would grate and use for cooking.

French onion seasoning for one potato bake

If you don't want to make a bulk batch of my French onion seasoning mix, here's how to make a small batch.

• 25 grams crispy fried onions (lightly crushed if they are quite large)
• 2.5 teaspoons onion granules - not onion salt
• 2 teaspoons cornflour
• 1 teaspoon vegetable bouillon powder
• ¼ teaspoon sugar (optional)

Measure these ingredients into a small bowl, and mix well to combine.

This makes approximately 5 tablespoons, which is sufficient for one potato bake.

Foodle Club top tips

Follow these handy tips to ensure your French onion potato bake always turns out perfectly:

• Slice the potatoes and onions thinly and evenly. Try to keep all the slices the same thickness. One-eighth of an inch is the perfect thickness. Thicker potatoes and onions will take longer to cook, so if yours are on the thicker side, leave the dish in the oven for a few extra minutes.
• Season both layers. Sprinkle salt and pepper lightly over the potatoes on both layers. If you only season the top layer, the bottom layer will be quite bland.
• Place the dish on a baking tray. This will catch any overflow (if there is any). This is especially important if you are using milk only; milk has a nasty habit of boiling over.
• Leave the dish undisturbed for the first 50 minutes. When you remove the tin foil, stick a knife into the potatoes; it should slide in with no resistance. If you think they are still not fully cooked, replace the tin foil and bake for a few minutes longer.
• Remove the lid to brown the potato bake. After the first covered cooking period, the potatoes will look a little pale and unappetising. Put them back into the oven, uncovered, to allow the dish to brown.

Serving suggestions

I prefer to eat the potato bake served hot. It makes a great accompaniment to a roast dinner, but there are a few more ways you could serve it:

• Barbeque side dish. Back in the day, no self-respecting braai (BBQ) was complete without either a potato salad or a potato bake to serve alongside the meat.
• A change from chips or French fries. I like to serve this potato bake with a piece of lightly battered fish and a helping of peas. It makes a nice change from the ubiquitous chips.
• A quick and easy supper. Next time you have sausages for supper, serve them with this potato bake and spoon some tamatie-smoor (South African tomato stew) over the top. When I make this at home, I always make sure there's enough left over for my husband's favourite lunch the next day - a messy sausage sandwich topped with a few spoonfuls of tomato stew (and served with a pile of serviettes on the side)!

Equipment tips

• The main item of equipment would be a casserole dish to assemble and bake the potato bake. It should have a lid if possible; otherwise, you could improvise and use a sheet of tin foil folded over the top of the dish.
• If you have a baking sheet, place the casserole on it before putting it in the oven to catch any overflow from the potato bake.
• I like to use a mandolin to slice the potatoes and onions (even though it gives me the heebie-jeebies whenever I use it). It makes slicing even slices so much easier.

Make ahead and freezing

• Assemble a few hours in advance. Cover and store in the refrigerator until you are ready to bake. If baking straight from the refrigerator, allow a few minutes of extra cooking time and check that the potatoes are completely tender before removing the lid and browning.
• To freeze the potato bake. I recommend cooking it first, up to the point where it needs browning and the potatoes are tender. Allow to cool completely, then cover the dish with foil and cling film and freeze for up to three months.
• Defrost overnight in the refrigerator, then reheat it covered in the oven until piping hot (about half an hour). Remove the lid for the final 10 to 15 minutes to brown the surface and allow the cheese to become golden and bubbly.

Please bear in mind that a cream-based potato bake may be slightly softer after freezing, but this method gives a better result than freezing the raw potatoes and cream.

FAQ

Save for later

If you would like to make this French onion 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.