Prepare Pastry for Single-Crust Pie. Line the unpricked pastry shell with a double thickness of heavy duty foil. Bake in a 450 degrees F oven for 8 minutes. Remove foil. Bake for 4 to 5 minutes more or until pastry is set and dry. Remove from oven. Reduce oven temperature to 325 degrees F. (Pie shell should still be hot when filling is added; do not partially bake pastry shell ahead of time.)
Meanwhile, in a large skillet cook bacon until crisp. Drain, reserving 2 tablespoons drippings. Crumble bacon finely; set aside. Cook sliced onion in reserved drippings over medium heat until tender but not brown; drain.
In a medium mixing bowl stir together the eggs, half-and-half, milk, salt, and nutmeg. Stir in the crumbled bacon and onion. Toss together shredded cheese and flour. Add to egg mixture; mix well.
Pour egg mixture into the hot, baked pastry shell. Bake in the 325 degrees F oven for 50 to 60 minutes or until a knife inserted near the center comes out clean. If necessary, cover edge of crust with foil to prevent overbrowning. Let stand 10 minutes. Garnish with tomatoes and parsley before serving. Makes 6 servings.
Pastry for Single-Crust Pie
In a medium bowl stir together flour and salt. Using a pastry blender, cut in shortening until pieces are pea-size. Sprinkle cold water over part of the flour mixture; gently toss with a fork. Push moistened dough to the side of the bowl. Repeat moistening flour mixture, 1 tablespoon at a time, until all is moistened (use 4 or 5 tablespoons total). Form dough into a ball. On a lightly floured surface, use your hands to slightly flatten dough. Roll dough from center to edges into a circle about 12 inches in diameter. To transfer pastry, wrap it around the rolling pin. Unroll pastry into a 9-inch pie plate. Ease pastry into pie plate, being careful not to stretch pastry. Trim pastry to 1/2 inch beyond edge of pie plate. Fold under extra pastry. Crimp edge as desired. Do not prick pastry. Bake as directed.