Chicken Pot Pie

INGREDIENTS

• 8 Tbs. (1 stick) unsalted butter, cut into ½-inch cubes
• ½ cup all-purpose flour
• 4 cups chicken stock
• ½ tsp. chopped fresh thyme
• 1 bay leaf
• ½ cup chopped yellow onions
• ½ cup chopped celery
• ½ cup peeled and chopped carrots
• ½ cup chopped white button mushrooms
• ½ cup chopped red-skinned potatoes
• 1 cup chopped cooked chicken
• ½ cup cooked fresh or frozen peas
• Salt and freshly ground pepper, to taste
• Four 6-inch squares frozen puff pastry
• 1 egg, beaten with 1 tsp. water