Mushroom and Onion Tart

Are you looking for a delicious and savory dish to impress your guests at your next dinner party? Look no further than this Mushroom and Onion Tart recipe! This dish is perfect for those who love the earthy flavors of mushrooms and the sweetness of caramelized onions. In this blog post, we will walk you through the steps to create this delectable tart, from preparing the crust to sautéing the vegetables. By the end of this post, you’ll be ready to wow your friends and family with this mouthwatering dish. Let’s dive in!


  • 1 sheet of puff pastry
  • 1 tablespoon olive oil
  • 1 onion, thinly sliced
  • 8 ounces of mushrooms, sliced
  • 2 cloves of garlic, minced
  • 1 teaspoon thyme
  • Salt and pepper to taste
  • 1/2 cup of grated Gruyere cheese
  • 1/4 cup of grated Parmesan cheese
  • 1 egg, beaten


  1. Preheat your oven to 400°F (200°C).
  2. Roll out the puff pastry on a baking sheet lined with parchment paper.
  3. Using a fork, poke holes in the pastry to prevent it from puffing up too much while baking.
  4. Heat the olive oil in a pan over medium heat.
  5. Add the sliced onions and cook until they are soft and caramelized, about 10 minutes.
  6. Add the mushrooms, garlic, thyme, salt, and pepper to the pan and cook for another 5 minutes.
  7. Spread the mushroom and onion mixture evenly over the puff pastry.
  8. Sprinkle the Gruyere and Parmesan cheese on top of the mixture.
  9. Brush the edges of the pastry with the beaten egg.
  10. Bake in the preheated oven for 20-25 minutes, or until the pastry is golden brown and the cheese is melted and bubbly.
  11. Remove from the oven and let it cool slightly before slicing and serving.

Additional Tips:

  • You can customize this tart by adding other ingredients like cooked bacon or spinach.
  • For a vegan version, you can substitute the cheese with a dairy-free alternative.
  • This tart is best served warm, but leftovers can be stored in the refrigerator and reheated in the oven.

By following these simple steps, you can create a delicious mushroom and onion tart that is perfect for a light lunch or as an appetizer for a dinner party. Enjoy!