Step-by-step instructions

Prepare to embark on a culinary adventure with these simple steps:

1. Preheat your oven to 400°F (200°C).
2. Roll out the puff pastry on a floured surface and place it in a tart pan. Gently press down and trim any excess pastry.
3. Brush the pastry with egg wash and set it aside.
4. In a skillet over medium heat, heat the olive oil and butter. Add the sliced onion, cooking for about 15-20 minutes until soft and caramelized.
5. Stir in the mushrooms, thyme, salt, and pepper. Cook until the mushrooms are tender and any moisture has evaporated.
6. Spread the onion and mushroom mixture evenly over the prepared pastry.
7. Evenly sprinkle the grated Gruyère cheese on top. If desired, drizzle with heavy cream for extra richness.
8. Bake for 25-30 minutes, or until the pastry is golden brown and the cheese is bubbly.
9. Allow the tart to cool slightly before slicing, and serve warm.

How to serve Rustic French Onion & Mushroom Tart with Gruyère

This tart shines on its own, but you can elevate your meal by pairing it with a crisp green salad drizzled with vinaigrette. Consider serving it alongside a light soup, like a classic French onion, to echo the flavors of the tart. For an extra touch, add a sprinkle of fresh herbs on top just before serving for a burst of color and flavor.

How to store

To keep any leftover tart fresh, allow it to cool completely, then store it in an airtight container in the refrigerator for up to three days. If you want to enjoy it later, this tart can be frozen before baking. Wrap it tightly in plastic wrap and aluminum foil; it should last in the freezer for a couple of months. When ready to bake, simply remove from the freezer and bake straight from frozen, adding a few extra minutes to the cooking time.

Helpful cooking tips

• For enhanced flavor, consider adding a splash of white wine to deglaze the skillet after caramelizing the onions.
• Make sure to slice the mushrooms evenly, ensuring they cook at the same rate.
• If you prefer a creamier texture, the optional heavy cream is a great addition, but you can omit it for a lighter version.

Creative twists

Elevate your tart with some variations! Try swapping out the Gruyère for a sharp cheddar or a tangy blue cheese for a different flavor profile. You can also experiment with adding other vegetables such as spinach or roasted red peppers for a twist. For a gluten-free version, use a gluten-free pastry or even a cauliflower crust.

FAQs

What is the prep time for this recipe?

Preparing this tart generally takes about 15-20 minutes, with an additional 25-30 minutes for baking.

Can I substitute the Gruyère cheese?

Absolutely! Cheddar, Swiss, or a combination of these cheeses can work beautifully in this dish.

How do I reheat the leftover tart?

To reheat, place individual slices in the oven at 350°F (175°C) for about 10-15 minutes, or until warmed through, preserving that crispy pastry texture.

Is this dish suitable for vegetarians?

Yes! The Rustic French Onion & Mushroom Tart is entirely vegetarian-friendly.

This recipe is not just a meal; it’s an experience that can bring the flavors of rustic French cuisine right to your table. Enjoy making, sharing, and savoring each delicious bite!