INGREDIENTS
2 tbsp
unsalted butter
1
shallot, thinly sliced
1
lb (455 grams) mushrooms, thinly sliced
Salt and pepper,
1
tablespoon (about 2 sprigs) fresh rosemary, chopped
1/2 cup
Parmesan cheese, grated
1
large egg, lightly beaten
1
sheet frozen puff pastry, thawed