STEP 2 - In medium saucepan, brown pork and beef with onion. Drain fat. Add remaining ingredients, except potatoes. Simmer, uncovered, for 20 minutes, stirring occasionally. Remove from heat. Remove bay leaf. Stir in mashed potatoes. Spread filling evenly into pie crust. Top with second crust; flute edges as desired. Cut slits in top crust to vent.