Ingredients
Scale
For the Tart:
- 1 sheet frozen puff pastry (about 9×9 inches), thawed
- 1 pound mixed mushrooms (cremini, shiitake, oyster, button), cleaned and sliced
- 2 tablespoons olive oil
- 1 tablespoon butter
- 1 large shallot, finely diced (or ½ medium onion)
- 3 cloves garlic, minced
- 2 tablespoons fresh thyme leaves (or 1½ teaspoons dried thyme)
- ¼ cup dry white wine (optional, or use vegetable broth)
- 3 tablespoons heavy cream or crème fraîche
- ¾ cup Gruyère cheese, shredded (or fontina, white cheddar, or goat cheese)
- ½ teaspoon salt (adjust to taste)
- ¼ teaspoon black pepper
- ⅛ teaspoon nutmeg (optional, but recommended)
- 1 egg, beaten (for egg wash)
- 2 tablespoons fresh parsley, chopped (for garnish)
- Flaky sea salt (for finishing, optional)
Instructions
- Preheat and prep: Preheat your oven to 400°F (200°C). Line a large baking sheet with parchment paper or a silicone baking mat. Remove the puff pastry from the refrigerator and let it sit at room temperature while you prepare the mushrooms (it should be cold but pliable).
- Prepare the mushrooms: Clean the mushrooms by wiping them with a damp paper towel (don’t wash them as they’ll absorb water). Remove any tough stems, especially from shiitake mushrooms. Slice all mushrooms to roughly the same thickness, about ¼-inch, so they cook evenly.
- Sauté the aromatics: Heat a large skillet over medium heat. Add 1 tablespoon olive oil and the butter. Once the butter melts and foam subsides, add the diced shallot. Cook for 2-3 minutes, stirring occasionally, until softened and translucent. Add the minced garlic and cook for another 30 seconds until fragrant.
- Cook the mushrooms: Increase heat to medium-high and add the remaining tablespoon of olive oil. Add all the sliced mushrooms at once (don’t worry if the pan seems crowded – they’ll shrink significantly). Season with salt and pepper. Cook without stirring for 3-4 minutes to allow the mushrooms to brown on one side. Then stir and continue cooking for 8-10 minutes, stirring occasionally, until the mushrooms have released their moisture, it has evaporated, and they’re golden brown and caramelized.
- Deglaze and finish the filling: Add the white wine (or broth) to deglaze the pan, scraping up any browned bits from the bottom. Let it cook for 1-2 minutes until mostly evaporated. Stir in the fresh thyme leaves and nutmeg if using. Remove from heat and stir in the cream or crème fraîche. Taste and adjust seasoning if needed. Let the mixture cool slightly for 5 minutes.
- Prepare the pastry base: Unfold the thawed puff pastry onto your prepared baking sheet. If it’s sticking or has creases, gently roll it out slightly with a rolling pin, but keep it roughly square or rectangular. Using a sharp knife, score a border about 1 inch from the edge all the way around the pastry, being careful not to cut all the way through – you’re just marking where the crust will be. Prick the inner rectangle all over with a fork (this prevents it from puffing up too much).
- Brush with egg wash: Beat the egg in a small bowl and brush it over the 1-inch border of the pastry using a pastry brush. This will create a golden, glossy crust when baked.
- Assemble the tart: Sprinkle about half of the shredded cheese (about 6 tablespoons) evenly over the inner rectangle of the pastry, staying within the scored border. This creates a flavorful base layer. Spoon the cooled mushroom mixture over the cheese, spreading it evenly but still keeping within the border. Top with the remaining cheese scattered over the mushrooms.
- Bake: Place the baking sheet in the preheated oven and bake for 20-25 minutes, until the puff pastry is golden brown, puffed around the edges, and cooked through on the bottom. The cheese should be melted and bubbly. If the edges are browning too quickly but the bottom isn’t done, reduce the oven temperature to 375°F and continue baking.
- Finish and serve: Remove from the oven and let cool for 5 minutes on the baking sheet. The tart will set slightly as it cools, making it easier to slice. Garnish with freshly chopped parsley and a sprinkle of flaky sea salt if desired. Slice into 6 pieces using a sharp knife or pizza cutter and serve warm or at room temperature.
Notes
- Pastry thickness: If your puff pastry seems very thin, you can stack two sheets together for a thicker, more substantial base.
- Moisture control: Make sure to cook the mushrooms long enough that all their liquid evaporates. Watery mushrooms will make the pastry soggy.
- Cheese alternatives: Feel free to experiment with different cheeses! Goat cheese, feta, brie, or a combination all work beautifully.
- Make it vegan: Use vegan puff pastry, omit the butter (use all olive oil), skip the cream or use cashew cream, and use vegan cheese.
- Gluten-free option: Use gluten-free puff pastry (available at specialty stores) or make a simple gluten-free crust.
- Serving temperature: This tart is delicious hot, warm, or at room temperature, making it perfect for parties and picnics.
- Scaling up: This recipe easily doubles if you’re feeding a crowd – just use two sheets of puff pastry and double all ingredients.
- Prep Time: 15 minutes
- Cook Time: 30 minutes
- Category: Appetizer
- Method: Baking
- Cuisine: French-American
- Diet: Vegetarian
Nutrition
- Serving Size: 1 slice (⅙ of tart)
- Calories: 285
- Sugar: 2g
- Sodium: 380mg
- Fat: 20g
- Saturated Fat: 8g
- Unsaturated Fat: 11g
- Trans Fat: 0g
- Carbohydrates: 19g
- Fiber: 2g
- Protein: 9g
- Cholesterol: 45mg