Chicken Potpies with Puff Pastry

INGREDIENTS

• 1 shallot, finely chopped
• 3 tablespoons extra-virgin olive oil
• 1 carrot, peeled and thinly sliced crosswise
• 1 small parsnip, peeled and sliced into rounds
• 1 russet potato, peeled and diced
• 1/2 cup dry white wine
• 1 1/2 cups chicken stock
• 1 pound boneless, skinless chicken breasts, cut into 1/2-inch pieces
• 3 thyme sprigs
• Coarse salt and freshly ground pepper
• 5 teaspoons cornstarch whisked with 2 tablespoons water
• 1/2 cup heavy cream
• 1 package (14 ounces) puff pastry, cut into four 4 1/4-inch squares
• 1 large egg, lightly beaten