This ultra-flaky Mushroom Tart is loaded with sharp cheddar cheese, fragrant thyme, and a hint of sweet balsamic vinegar. Each bite bursts with rich, savory flavors, all served on a golden, buttery puff pastry base, making it perfect as a vegetarian appetizer or snack!
Preheat oven to 400 degrees. Line a baking sheet with parchment paper.
Heat a large skillet over medium high heat. Add in oil and butter and melt.Add in onion and sauté for 3-4 minutes.
Next add in mushrooms and cook for 3-4 minutes undisturbed. Stir then continue to cook for 3-4 more minutes or until the mushrooms are tender and golden brown. Stir in garlic and balsamic and cook for an additional minute. Remove the mushrooms from the heat and set aside.
Roll out the puff pastry onto the prepared baking sheet. Using a knife score the edges of the puff pastry to create a crust. Do not cut all the way through. Top with cheddar cheese, leaving a border around the edges.
Spread the cooked mushrooms on top. Brush the sides of the puff pastry with the whisked egg.Cook for 25-30 minutes or until the crust is golden brown and the center or the puff pastry is cooked and crisp.
Allow it to cool for 5-10 minutes before slicing into squares or triangles.Serve with fresh thyme and enjoy!