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Hi Bold Bakers!
WHY YOU’LL LOVE THIS RECIPE: You’ll want to make this richly-flavored Mushroom and Thyme Leaf Tart on repeat through the autumn and winter months. It’s a crowd-pleaser that’s ideal for a holiday brunch, or pair it with soup and a salad for a cozy lunch or dinner. Enjoy any leftover tart the next day for breakfast! Earthy mushrooms and woodsy thyme bring fall vibes to this dish, and the richly satisfying custard baked in buttery pastry is ideal for chillier days. Follow our easy recipe, and you’ll be taking a lovely, piping-hot Mushroom and Thyme Leaf Tart out of your oven in no time!
Table of Contents
- What is a Mushroom and Thyme Leaf Tart?
- Tools You Need to Make a Mushroom and Thyme Leaf Tart
- Key Ingredients and Why
- How to Make a Mushroom and Thyme Leaf Tart
- Can I Make a Mushroom and Thyme Leaf Tart in Advance?
- How to Store a Mushroom and Thyme Leaf Tart
- Gemma’s Pro Chef Tips
- More Brunch Recipes
What is a Mushroom and Thyme Leaf Tart?
- A Mushroom and Thyme Leaf Tart has a savory, creamy custard filling flavored with cremini mushrooms, thyme, and Parmesan cheese baked in a shortcrust pastry.
- Shortcrust is an irresistibly tender crumbly pastry. “Short” here means the crust falls apart easily into small pieces because it has a higher fat content than standard pie crust. Additionally, shortcrust recipes do not include water. Therefore, gluten strands are not formed, which gives the crust a crumbly texture.
- The first records of shortcrust pastry date back to 14th century England. “Short” in the vocabulary of the time meant easily crumbled, especially compared to “long” crusts of the time which were sturdy, tougher pastries.
- Simple types of egg tarts go back as far as ancient Greece and Rome. Forms of savory egg custard tarts are popular around the world and include French quiches and German zwiebelkuchen.
Tools You Need to Make a Mushroom and Thyme Leaf Tart
- Mixing bowl
- Measuring cups and measuring spoons
- Measuring jug
- 9-inch tart dish
- Parchment paper
- Pie weights (or dried beans)
- Large frying pan
Key Ingredients for Mushroom and Thyme Leaf Tart and Why
Crust for Mushroom and Thyme Leaf Tart
- All-purpose flour has protein content around 9-11% which is perfect for forming the needed amount of gluten to hold shape and handle moisture without being chewy.
- Learn how to measure flour correctly to be sure you get the perfect amount every time!
- Butter provides a high percentage of fat and a low percentage of water to form a crust with a crumbly texture. And you can’t beat the taste of pastry made with butter.
- Making your own butter is easier than you think!
The egg binds the shortcrust ingredients together.
Whole milk provides moisture and flavor.
The acid in vinegar helps minimize gluten formation, giving the crust a crumbly, tender texture.
Filling for Mushroom and Thyme Leaf Tart
- Cremini mushrooms add a rich, earthy taste to the tart. Their natural umami (savory) note is a wonderful complement to the tart’s mild dairy flavors.
- The texture of cremini mushrooms is more satisfying and they have a meatier bite than white button mushrooms.
- Eggs bind the ingredients together to form a cohesive tart filling. They give the filling a pleasantly creamy, custardy mouthfeel.
- Make sure to use good quality, large eggs.
Whole milk and heavy cream
- Using a combination of whole milk and heavy cream in the tart filling gives it a perfectly balanced texture.
- The mix of whole milk (3.5% fat content) and heavy cream (which has a 30-36% fat content) makes the filling thick and velvety, but not heavy or dense.
- Versatile thyme adds a woody, slightly lemony, and peppery zip that offsets the earthy mushrooms perfectly.
- Ideally, use fresh thyme leaves in this recipe for the best flavor. You can substitute ground (dried) thyme. The rule of thumb is to use one-third of the amount of fresh herbs, so you’d use one teaspoon of ground thyme here.
Delightfully nutty and salty Parmesan cheese adds a zing of tanginess to the Mushroom and Thyme Leaf Tart.
How to Make a Mushroom and Thyme Leaf Tart
- Make the crust: Rub the cold butter into the flour and salt mixture until crumbly. Mix wet ingredients in a measuring jug. Combine wet and dry ingredients, and using your hands bring the dough together until it forms a ball.
- Shape the crust: On a floured surface, shape the dough into a disc. Wrap in cling film and let rest for at least one hour.
- Blind bake the crust: Preheat the oven to 350°F (180°C). Roll out the chilled crust and place it in the tart dish. Pierce the bottom of the pastry all over with a fork. Line the pastry with parchment paper and fill with pie weights or dried beans. Bake for 20 to 25 minutes, until dry. Set aside.
- Prepare the filling: Over high heat, sauté the mushrooms in butter until browned, about 3 minutes. Set aside. Whisk the eggs, milk, and cream, and stir in the Parmesan, thyme, mushrooms, salt and pepper.
- Bake the tart: Bake for 25 minutes, until set. Serve warm.
Can I Make a Mushroom and Thyme Leaf Tart in Advance?
- Yes, you can make elements of this easy mushroom tart recipe in advance to shorten prep time on the day of serving. Note that the tart tastes best when you bake it the day it’s being served.
- Prepare the shortcrust pastry, roll it out, wrap in cling film, and refrigerate for 24 hours or freeze for up to 8 weeks.
- You can also sauté the mushrooms and refrigerate them for up to two days. Let them come to room temperature before mixing with the other filling ingredients.
How to Store a Mushroom and Thyme Leaf Tart
- Store any leftover tart covered in the fridge for up to three days.
- Reheat at 300°F (150°C) for 15 minutes.
Why does this Mushroom and Thyme Leaf Tart use cold eggs instead of room-temperature eggs?
Unlike quiche that requires room temperature eggs for easy and smooth mixing, this Mushroom and Thyme Tart uses cold eggs to prevent curdling, maintain texture, enhance binding, and provide even distribution.
- Unlike a quiche which mix pre-cooked and cooled or raw ingredients then bake them together in the oven, this tart mixes freshly cooked mushroom with raw eggs. Cold eggs will ensure that they don’t get cooked easily when other warm ingredients don’t get cooled for long enough, which prevents eggs from curdling and contributes to the even distribution of eggs.
- Cold eggs will also bind other ingredients better when baked.
Can I make Mushroom and Thyme Leaf Tart without eggs?
- Yes, you can make Mushroom and Thyme Leaf Tart without eggs! Chickpea flour, or garbanzo bean flour, sets up while baking and creates a similar texture to eggs. Its neutral flavor means it can easily substitute the eggs.
- See my 12 Best Egg Substitutes for Baking Recipes and How to Use Them for more information.
Can I use a gluten-free crust with this tart?
Yes, you can The Flakiest Gluten-Free Pie Crust recipe. Just be sure to leave out the powdered sugar for this savory recipe.
How can I avoid a grainy or curdled tart?
- Overcooking is the main culprit here. Be sure to cook the tart at 350°F (180°C) and take the tart out of the oven when it’s just set in the middle.
- Do not leave out or substitute the cream in this recipe. The fat in the cream protects the egg protein from coagulating while cooking.
How do I keep my tart from being soggy?
- Blind baking helps give you a crisp crust.
- Additionally, be sure to sauté the mushrooms until they brown. The juices from undercooked vegetables can make the filling watery.
Gemma’s Pro Chef Tips
- You can use a pastry cutter to add the cold butter into the flour mixture or use your fingers to massage the butter into the flour.
- The dough can be frozen for up to 8 weeks. When ready to use, let it defrost at room temperature and then blind bake and use as normal.
- Feel free to experiment with different fillings. Sauté onion, garlic, or shallots along with the mushrooms, and if desired add diced ham or crumbled bacon. Switch up the Parmesan for gruyere cheese or my Homemade Mozzarella Cheese.
- Substitute in chopped shiitake or oyster mushrooms if you prefer, or use a mushroom mixture. Mushrooms that are a few days older usually have even better flavor. Sautéing the mushrooms first (in olive oil if you like) not only enhances their flavor but releases excess moisture so the mushrooms won’t make the tart soggy.
- Make sure to poke the crust with a fork before baking to release steam.
More Savory Brunch Recipes
Mushroom and Thyme Leaf Tart Recipe
For the Shortcrust Pastry
- 2 ¼ cups (11 ¼ oz/ 320 g) all-purpose flour
- 1 teaspoon salt
- 2 sticks (8 oz/227 g) cold butter, cubed
- 1 large egg, cold
- About 3 tablespoons (1 ½ fl oz/ 45 ml) whole milk
- 2 teaspoons vinegar
For the Mushroom Filling
- 3 tablespoons (1 ½ oz/43g) butter
- 8 oz (225 g) crimini mushrooms, finely chopped
- 3 large eggs, cold
- 1 large egg yolk, cold
- 1 cup (8 fl oz/ 240 ml) whole milk
- 1 cup (8 fl oz/ 240 ml) heavy cream
- About ⅔ cup (2 oz/ 57 g) parmesan cheese
- 1 tablespoon fresh thyme, chopped
- salt and freshly ground pepper, to season
Make the Pastry
- Put the flour and salt in a large mixing bowl. Rub in the cubed butter between your forefingers until the mixture resembles coarse breadcrumbs.
- In a separate measuring jug, whisk together the egg, milk, and vinegar.
- Add the wet ingredients into the dry. Using your hands, bring the mixture together until it forms a dough – it should be soft but not sticky. Shape the dough into a ball on a flour-dusted work surface, flatten into a disc and cover in cling film. Set aside in the fridge for at least 60 minutes to rest. The pastry can be made up to 24 hours in advance. It also can be frozen for up to 8 weeks.
- Preheat the oven to 350°F (180°C). Now prepare the pastry to be blind baked.
- On a floured surface, roll the chilled pastry to about ¼-inch thick. Lay into a shallow 9-inch tart dish. Trim the edges of the pastry to tidy it up.
- Dock the pastry by piercing it with a fork to release the steam and line it with parchment paper and baking beans. (See how to Blind Bake Pastry)
- Bake the pastry for 20 to 25 minutes or until the pastry doesn't look wet and raw. Set aside while you make the filling.
Make the Mushroom Filling
- In a large frying pan over high heat add the butter and allow to sizzle. Sauté the mushrooms until browned, about 3 minutes. Set aside to cool down.
- In a separate bowl whisk together the eggs, yolk, milk and cream.
- Add in the cheese, thyme and cooled mushrooms. Lastly, season generously with salt and pepper.
- Bake the tart for roughly 25 minutes or until set in the middle.
- Allow to cool down slightly before serving with a side salad. Store any leftovers in the fridge for up to 3 days.