Ingredients

• 12 ounces cremini mushrooms
• 0.5 reds onion
• 1 tablespoon olive oil
• 1 tablespoon unsalted butter
• 2 tablespoons low-sodium soy sauce
• 1 teaspoon dried thyme
• 2 arlics cloves , minced
• salt and freshly ground black pepper to taste
• 1/2 , 17.3 ounce
• 1.5 cups shredded Gruyere cheese
• 1 large egg , beaten
• 1 teaspoon dried thyme , optional

Instructions

1. 1 Preheat the oven to 400 degrees F (200 degrees C). Line a baking sheet with parchment paper.
2. 2 Cut mushrooms into 1/4-inch-thick slices (don't cut too thinly).
3. 3 Heat olive oil and butter in a large skillet over medium heat. Add mushrooms and onion and cook, stirring occasionally, until mushrooms are golden and onions are soft and translucent, 6 to 8 minutes.
4. 4 Stir in soy sauce, thyme, and garlic and cook until fragrant, 30 to 60 seconds. Season with salt and pepper; set aside.
5. 5 Unfold puff pastry sheet onto a lightly-floured work surface. Gently pat down or roll out dough with a rolling pin into a 10x10-inch square. Using a sharp knife, score a line about 1/2 inch from all edges to create a border, being careful not to cut all the way through. Use a fork to generously prick pastry sheet all over inside the border.
6. 6 Transfer puff pastry to the baking sheet, and brush the borders with beaten egg. Evenly spread Gruyere cheese inside the border, and top with mushroom mixture.
7. 7 Bake until tart is puffed and lightly browned, 10 to 12 minutes. Garnish with additional thyme, and serve warm.

Nutrition per serving