Buttery Crab Pot Pies

INGREDIENTS

• 2 tablespoons all-purpose flour, plus more for dusting
• 1 egg, beaten with 1 teaspoon water, to brush pastry
• 1 small yellow onion, chopped
• 1 1/2 cups milk
• 8 tablespoons (1 stick) butter
• 1/4 cup clam juice
• 1/2 pound crabmeat, well drained and picked clean of shells
• Salt and cracked black pepper
• 2 sheets frozen puff pastry, thawed
• 1/4 cup medium-dry sherry
• 1 cup sliced mushrooms
• 1 cup frozen peas