In a large pot or Dutch oven, melt the butter and saute the onions over medium-low heat for 10 to 15 minutes, until translucent.
Add the flour and cook over low heat.
Press one of the pie crusts into the bottom of a 9-inch pie dish.
Spoon a layer of gravy (about ⅓ cup) into the crust.
Layer the cooked vegetables and chicken.
Bring to a boil, then cover and let it simmer gently over low heat for one hour.
Cut slits in the top of the pastry.
Preheat oven to 350F degrees.
Place chicken breasts on a baking sheet sprayed with nonstick cooking spray.
Drizzle chicken breasts with olive oil.
