Mushroom Tart Recipe
This savory puff pastry mushroom tart is flaky, buttery, and layered with caramelized mushrooms and onions, garlic, thyme, and melty cheese. It's an easy, crowd-pleasing vegetarian tart that's perfect for holiday entertaining, brunch, or a weeknight.
Servings: 9 servings
Calories: 261kcal
Equipment
- 1 large baking sheet
Ingredients
- 1 sheet puff pastry, thawed according to package instructions
- 1 egg + 1 Tablespoon water, beaten together
- 3 Tablespoons extra-virgin olive oil, divided
- 1 medium yellow onion, thinly sliced into half moons
- 1 Tablespoon white wine vinegar
- 2 garlic cloves, minced
- 2 Tablespoons fresh thyme, chopped, or 2 teaspoons dried thyme
- salt & pepper
- 8 ounces cremini mushrooms, thinly sliced *Remove any dirt with a damp paper towel, but don't rinse them under water, or they will become soggy.
- ¾ cup Gruyère cheese, grated
- 2 Tablespoons Parmesan cheese, grated
Instructions
Prep Aromatics & Mushrooms
- Heat 2 tablespoons olive oil in a large frying pan over medium. Add sliced onion and adjust heat to medium-low. Cook until onion is soft and golden brown, around 20 minutes, stirring every once in a while.
- Add vinegar, garlic, thyme, pinch of salt and pepper, and cook for another 2 minutes.
- Transfer onion mixture to a bowl, and set aside to cool.
- Use a paper towel to wipe out your frying pan. Add remaining tablespoon of olive oil, and adjust heat to medium-high. Add mushrooms to pan without overcrowding them. To get a nice sear, do not touch the mushrooms for 4-5 minutes. Quickly flip the mushrooms, and sear the other side for 2 minutes, being sure not to stir/move them around. Remove mushrooms from heat and let cool for 10-15 minutes.
Assemble Puff Pastry
- Preheat the oven to 400°F. Line a large baking sheet with parchment paper.
- Lightly roll out the puff pastry on your parchment paper. Using a knife, score the puff pastry about 1 inch from the edge. Brush border with the egg wash, using a pastry brush. Prick the center of the dough all over with a fork (this prevents the crust from becoming soggy). If your mushrooms have cooled, you can go directly to the next step. Otherwise, place your prepped pastry in the fridge to keep it cold while you wait.
- Sprinkle grated Gruyère cheese evenly over pastry. Spoon caramelized onion mixture on top of cheese, followed by cooked mushrooms (leaving any liquid behind in the pan). Use a rubber spatula to spread onion and mushrooms evenly over the pastry. Top with the grated Parmesan cheese.
- Bake for 30 minutes, until tart border becomes deep golden brown. Season to taste with additional salt and pepper, and slice into 9 squares. Serve warm or at room temperature.
Video
Notes
- Keep the dough cold right up until baking to protect the butter layers and ensure proper rising.
- Storage: Store leftovers in an airtight container for up to 3 days. Let the tart cool completely before refrigerating so the pastry doesn't steam itself and turn soft.
- Reheating instructions: Reheat slices in a toaster oven or oven at 350°F for around 10 minutes. For maximum crispiness, place slice directly on a preheated baking sheet. Avoid reheating in the microwave if at all possible, as the pastry will become soft.
Nutrition
Calories: 261kcal | Carbohydrates: 15g | Protein: 7g | Fat: 19g | Saturated Fat: 6g | Polyunsaturated Fat: 2g | Monounsaturated Fat: 11g | Trans Fat: 0.002g | Cholesterol: 31mg | Sodium: 174mg | Potassium: 177mg | Fiber: 1g | Sugar: 1g | Vitamin A: 214IU | Vitamin C: 4mg | Calcium: 145mg | Iron: 1mg
