Preheat oven to 375 degrees F (190 degrees C). Line a baking sheet with parchment paper.
Unfold the puff pastry and place on the prepared baking sheet. Score a 1-inch border around the edge of the puff pastry.
In a large skillet, heat the olive oil over medium heat. Add the onion and garlic and cook until softened, about 5 minutes. Add the mushrooms, oregano, thyme, salt and pepper and cook until the mushrooms are softened, about 5 minutes.
Add the spinach and cook until wilted, about 3 minutes. Remove from heat and set aside.
Spread the mushroom-spinach mixture on the puff pastry within the 1-inch border. Sprinkle the mozzarella and Parmesan cheese over the top.
Brush the egg around the 1-inch border of the puff pastry. Bake in preheated oven for 25 minutes, or until the pastry is golden brown.
Let cool for 10 minutes before slicing and serving.
Interesting Facts
The name “torta” comes from the Italian word for “cake”.
Mushrooms provide a rich, earthy flavor to the dish.
Spinach adds a pop of color, texture and nutrition.