Chicken Pot Pie

In 2-quart saucepan, melt butter over medium heat. Stir in flour, onion, salt and pepper. Cook, stirring occasionally, until mixture is bubbly; remove from heat. Stir in broth and milk. Heat to boiling, stirring constantly. Boil and stir 1 minute. Stir in chicken and Veg-all; remove from heat. Heat oven to 425°F. East pie crust into ungreased 9-in square pan. Pour chicken mixture into pastry-lined pan. Place second pie crust over chicken mixture. Turn edges of pastry under and flute. Bake about 35 minutes or until golden brown.