→ Filling
01 -
2 tablespoons unsalted butter
02 -
1 tablespoon olive oil
03 -
1 medium onion, finely chopped
04 -
3 cloves garlic, minced
05 -
16 ounces mixed mushrooms (cremini, shiitake, button), sliced
06 -
2 tablespoons all-purpose flour
07 -
1 cup vegetable broth or chicken broth
08 -
1 teaspoon Dijon mustard, optional
09 -
1 teaspoon fresh thyme leaves, plus extra for garnish
10 -
Salt and freshly ground black pepper, to taste
11 -
1 cup Gruyère cheese, grated
→ Crust and topping
12 -
1 sheet puff pastry, thawed
13 -
1 large egg, beaten (for egg wash)