Heat oven to 425 degrees. Prepare pie crusts using package directions for two-crust pie using 9" pie pan.
In medium saucepan, melt margarine over medium heat. Add onion; cook 2 minutes or until tender. Stir in flour, salt and pepper until well blended. Gradually stir in broth and milk, cook stirring constantly until bubbly and thickened.
Add chicken/turkey and mixed vegetables; remove from heat. Spoon chicken mixture into crust-lined pan. Top with second crust and flute edges, cut slits in several places.
Bake at 425 degrees for 30-40 minutes or until crust is golden brown. Let stand 5 minutes before serving.