French Onion Mushroom Tart

Instructions

Step 1: Make the Tart Crust

1. Prepare the Dough: In a large bowl, combine the flour and salt. Add the cold, cubed butter and mix using a pastry cutter or your fingers until the mixture resembles coarse crumbs.
2. Add Ice Water: Gradually add ice water, one tablespoon at a time, mixing until the dough comes together. Be careful not to overwork it.
3. Chill: Form the dough into a disk, wrap it in plastic wrap, and refrigerate for at least 30 minutes.

Step 2: Caramelize the Onions and Sauté the Mushrooms

1. Cook the Onions: In a large skillet, heat olive oil over medium heat. Add the sliced onions and a pinch of salt. Cook, stirring occasionally, for about 15-20 minutes, until the onions are golden brown and caramelized.
2. Add Mushrooms: Stir in the sliced mushrooms and cook for an additional 5-7 minutes until they are tender and any liquid has evaporated. Add minced garlic and thyme, cooking for another minute. Season with salt and pepper. Remove from heat and let cool slightly.

Step 3: Preheat the Oven

1. Preheat Oven: Preheat your oven to 375°F (190°C).

Step 4: Roll Out the Tart Crust

1. Roll the Dough: On a lightly floured surface, roll out the chilled dough to fit a 9-inch tart pan. Press the dough into the pan, trimming any excess from the edges. Prick the bottom with a fork to prevent bubbling.
2. Blind Bake: Place a piece of parchment paper over the crust and fill it with pie weights or dried beans. Bake for 15 minutes, then remove the weights and parchment and bake for an additional 5-7 minutes until lightly golden. Remove from the oven and let cool slightly.

Step 5: Prepare the Filling

1. Mix Eggs and Cream: In a bowl, whisk together the eggs and heavy cream until well combined. Stir in the shredded Gruyère and grated Parmesan cheese.
2. Combine Ingredients: Add the cooled mushroom and onion mixture to the egg and cream mixture, stirring until evenly combined.

Step 6: Assemble and Bake the Tart

1. Fill the Tart: Pour the filling into the pre-baked tart shell, spreading it evenly.
2. Bake: Bake the tart in the preheated oven for 30-35 minutes, or until the filling is set and the top is golden brown.

Step 7: Serve

1. Cool and Slice: Allow the tart to cool for a few minutes before slicing. Serve warm or at room temperature, garnished with fresh thyme or parsley if desired.

Tips for the Perfect French Onion Mushroom Tart

• Caramelization: Be patient while caramelizing the onions. The longer they cook, the sweeter and richer they become.
• Cheese Options: Feel free to experiment with different cheese varieties, such as cheddar or feta, to customize the flavor.
• Storage: Leftover tart can be stored in the refrigerator for up to 3 days. Reheat in the oven for the best texture.

Conclusion

The French Onion Mushroom Tart is a delightful blend of flavors and textures that brings a touch of sophistication to any meal. Whether served as an appetizer or a main dish, it’s sure to impress your guests and family alike. Enjoy this savory tart with a fresh salad or your favorite side for a well-rounded meal that showcases the best of French cuisine!