In large saucepan, sauté onion, carrot, potato and celery in butter until tender. Add flour and seasonings until blended; gradually add broth. Bring to a boil; cook and stir for 2 minutes or until thickened. Stir in turkey, peas and yogurt; divide mixture among four ungreased 5-inch pie plates. Divide pastry into quarters. On a lightly floured surface, roll each quarter into a 6-inch circle; place over filling. Trim, seal and flute edges; cut slits to vent. Cover and freeze two potpies for up to 3 months. Bake the remaining potpies at 375° for 18 to 22 minutes or until golden brown. Let stand for 10 minutes before serving. To use frozen potpies: Remove from the freezer 30 minutes before baking. Cover edges of crusts loosely with foil; place on a baking sheet. Bake at 375° for 30 minutes. Remove foil; bake 15-20 minutes longer or until golden brown and filling is bubbly.