* berries can be fresh or frozen. PARTIALLY thaw the strawberries, if frozen. DO NOT DRAIN. Cut strawberries in half. In a large mixing bowl, stir together the flour and cornstarch. Add strawberries and their juice, fresh or frozen raspberries and fresh or frozen blueberries. Gently toss till berries are coated. If using frozen berries, let it stand for 15 to 30 minutes or until fruit is partially thawed but still icy. Prepare and roll out pastry for a lattice-top pie. Line a 9-inch pie plate with 1/2 of the pastry. Stir berries; transfer to the pastry-lined pie plate. Trim the pastry to 1/2 inch beyond the edge of the plate. Top with lattice crust. Seal and crimp the edges. To prevent overbrowning, cover the edge of the pie with foil . Preheat oven to 375~F. Bake for 25 minutes (for fresh fruit); 50 minutes (for frozen fruit). Remove foil. Bake for 20-25 minutes more (for fresh fruit); 20-30 minutes (for frozen fruit) or until the top is golden and juices are bubbly. Cool on wire rack. Makes 8 servings.