Cheesy mushroom and onion galette

What is a galette?

A galette is a rustic, free-form French pie that can be either sweet or savoury. It is made from a single sheet of pastry, with the edges folded over the filling to leave the centre uncovered.

Because it is assembled directly on a baking tray, there is no pie dish, blind baking or fluting involved. This makes it an easy alternative to a traditional tart while still looking impressive on the table.

My savoury mushroom galette combines mushrooms and softened onions with cream cheese, Cheddar and thyme, all enclosed in light, buttery pastry. I use a similar filling in my mushroom-stuffed chicken en croûte recipe.

The galette takes roughly an hour to prepare and bake. There is half an hour chilling time for the pastry, but you can use this time to cook the filling.

• The pastry takes only a few minutes to mix but needs to rest in the refrigerator for 30 minutes.
• You can prepare the mushroom filling while the pastry rests. Let it cool before assembling the galette so that it does not soften the pastry.
• Once assembled, the galette takes 20 to 25 minutes to bake.

Why I love this cheesy mushroom galette

A mushroom galette is one of my favourite savoury pies to make, and I think you'll love it too.

• The combination of mushrooms, onions and cheese works beautifully. A layer of cream cheese adds richness, while grated Cheddar melts over the mushroom filling.
• There is no pie dish or blind baking involved. Simply roll out the pastry, add the filling and fold the edges over to form the crust.
• It is made with ordinary, readily available ingredients. There is no need to search for expensive wild mushrooms or specialist cheeses.
• The homemade butter pastry is light, flaky and full of flavour. And because the galette is meant to look rustic, you don't have to worry about shaping a perfect pastry case.
• You can serve it hot or cold. Enjoy it with a salad as a light lunch or vegetarian main course, or cut it into smaller slices for a starter, picnic or buffet.
• It looks impressive without being difficult to make. The free-form pastry and visible mushroom filling make a lovely centrepiece for the table.

Ingredients for a mushroom galette

**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.**

Filling

• Mushrooms - you can use any type of mushrooms. I used a mixture of small portobello (chestnut or cremini) mushrooms and white button mushrooms, but you can use whatever mushrooms you have available. Slice them approximately one-quarter of an inch (about half a centimetre) thick.
• Onions - I used white onions, but red onions will give the filling a slightly sweeter flavour. Cut them in half (root to tip), then slice them into thin semi-circles.
• Garlic - use freshly minced garlic or ready-minced garlic from a jar.
• Cream cheese - use plain, full-fat cream cheese. You could use garlic and herb cream cheese for extra flavour. It is spread over the pastry before the mushroom filling is added and forms a barrier that helps protect the pastry from excess moisture.
• Cheddar cheese - grate the cheese before sprinkling it over the mushroom and onion filling. You can substitute another firm cheese that melts well. I like Cheddar because it is readily available, but you could use Gruyère or Stilton instead.
• Butter - for cooking the onions and mushrooms. I recommend using unsalted butter so that you can control the amount of salt in the filling.
• Fresh thyme - fresh thyme flavours the filling and can also be used as a garnish. If you do not have fresh thyme, substitute one teaspoon of dried thyme in the filling, but omit the garnish.
• Salt and black pepper - for seasoning. Adjust the amount to suit your own taste.

For finishing

• Egg - beaten and brushed over the pastry to give it a glossy, golden finish.
• Sesame seeds - sprinkled over the pastry before baking. These are optional.

Pastry

• Flour - use plain flour (all-purpose flour in the US). Don't use self-raising flour or add baking powder; this is a shortcrust pastry and is not intended to rise.
• Butter - unsalted butter gives the pastry the best flavour and allows you to control the amount of salt. You can substitute block margarine, although the flavour will be slightly different.
• Salt - enhances the flavour of the pastry. You can adjust the amount to suit your own taste.
• Ice cold water - helps keep the butter cold and prevents too much gluten from developing, resulting in light, tender pastry. Add it gradually because you may not need all of it.

How to make a savoury mushroom galette

This recipe will make one approximately 12-inch diameter mushroom galette, which can be cut into 12 slices.

Make the pastry

Step 1: Cut the butter into cubes and place it in a mixing bowl with the flour and salt.

Step 2: Using your fingertips, rub the butter into the flour until the mixture resembles fine breadcrumbs.

Rubbing the butter into the flour coats the flour particles with fat and limits gluten development when the water is added. This helps to produce light, tender pastry.

Step 3: Add most of the water and mix with a flat-bladed knife until the mixture starts to come together in a shaggy dough. Add the remaining water only if needed.

Step 4: Tip the dough onto a lightly floured surface and gently press it together with your fingertips to form a soft ball. Do not knead the dough.

Place the dough into a plastic bag or cover it with plastic wrap and place it into the refrigerator to rest for 30 minutes.

Avoid kneading the dough because this develops the gluten and may make the cooked pastry tough rather than light and tender.

Make the filling

Prepare the filling while the pastry is resting.

Step 5: Melt the butter in a frying pan over low heat and add the onions. Cover the pan with a lid and allow the onions to soften gently for 8 to 10 minutes. Stir occasionally and do not allow them to brown.

Step 6: After the onions have cooked for 5 to 7 minutes, add the thyme and garlic. Continue cooking for another 3 minutes.

Step 7: Add the mushrooms, replace the lid and continue cooking over low heat for 6 to 7 minutes, or until the mushrooms have softened and released their moisture. Stir occasionally. the onions are done, add the mushrooms,

Season with salt and black pepper to taste, then set the filling aside to cool.

Assemble the galette

Step 8: Remove the pastry from the refrigerator and roll it out on a lightly floured surface into a circle approximately 14 inches (36 cm) in diameter and one-eighth of an inch thick (about the thickness of a one-pound coin). Spread the cream cheese over the centre, leaving a 2-inch border around the edge.

Step 9: Spoon the cooled mushroom filling over the cream cheese. If there is any liquid remaining in the pan, leave it behind to prevent the pastry from becoming soggy.

Step 10: Sprinkle the grated cheese evenly over the mushroom filling.

Step 11: Carefully fold the pastry border up and over the edges of the filling. Use a spatula to help lift the pastry if necessary.

Bake the galette

Step 12: Transfer the galette to a baking tray lined with baking parchment. Brush the edges of the pastry with beaten egg and sprinkle with sesame seeds.

Step 13: Bake the galette in a preheated oven (200C / 400F) for 20 - 25 minutes until the edges of the pastry are crisp and golden brown.

Top tip - Roll out the pastry directly on a sheet of baking parchment and assemble the galette on the paper. The pastry may initially overlap the edges, but it will fit once the border has been folded over the filling. You can then lift the galette and parchment onto the baking tray together.

Serve the mushroom galette either hot or cold.

How to prevent a soggy mushroom galette

Here's how to ensure that your galette turns out with a crispy pastry base:

• Cook the mushrooms until they have released their moisture. If they are only partially cooked, they will continue to release liquid in the oven, which can soak into the pastry.
• Leave any excess liquid behind in the pan. Use a slotted spoon if necessary when transferring the filling to the pastry.
• Allow the filling to cool completely. A hot filling can soften the butter in the pastry before the galette goes into the oven.
• Spread the cream cheese over the pastry before adding the filling. This provides an additional barrier between the pastry and the mushrooms.

Equipment tips

• Use a frying pan with a lid. Covering the onions with a lid while they cook helps them soften faster.
• Use a sharp knife and a chopping board to protect your work surface while cutting up the onions and mushrooms.
• A large mixing bowl is useful for making pastry because it enables you to get your hands in to rub the butter into the flour without getting it all over the work area.
• If you don't have a rolling pin, a clean empty wine bottle makes a good substitute.

Pastry tips and guides

If you enjoy making pastry, or if you're a beginner wanting to discover a few tips and techniques, you might find the following links helpful:

• If you've ever wondered how much pastry you need to line a particular dish, my shortcrust pastry calculator will work it out for you. Simply enter the dimensions of your dish (either in inches or centimeters) and select whether you want to line the dish, add a lid, or make enough pastry for a lid only. The calculator will work out how much flour and fat you will need.
• The ultimate guide to pastry explains how ingredients and techniques affect the results you get when making homemade pastry. Find out why pastry sometimes goes wrong, which pastry to use for different recipes, and the simple rules that will help you make light, crisp pastry.
• How to make shortcrust pastry provides you with lots of tips for making shortcrust pastry for pies, tarts and more. Once you've tasted your own pastry, you might find yourself reaching for the ready-made kind a lot less often.

Mushroom galette FAQ

Save for later