Mushroom Turnovers

INGREDIENTS

• 2 Tbs. unsalted butter
• 2 Tbs. olive oil
• 3 Tbs. finely chopped shallot
• 12 oz. cremini mushrooms, finely chopped
• 1 1/2 tsp. chopped fresh thyme
• 1 1/2 tsp. chopped fresh rosemary
• Kosher salt and freshly ground pepper, to taste
• 1/2 cup heavy cream
• 1 oz. Gruyère cheese, grated
• 1 batch double-crust pie dough, divided into 2 disks and chilled (see related recipe at left)
• 1 egg, lightly beaten with 1 Tbs. water