1. Preheat oven to 425ºF.
2. Sift together dry ingredients.
3. Cut in margarine with a pastry blender or 2 knives.
4. Add buttermilk all at once; blend with a fork just until flour is moistened and dough pulls away from the side of the bowl.
5. Turn out onto a lightly floured board or wax paper. Knead lightly for 30 seconds.
6. Roll out to a thickness of ½ inch. Cut with a 2-inch round cutter. Place 1 inch apart on a baking sheet. Bake 12-15 minutes.
Food exchanges per 1 biscuit serving: 2/3 BREAD, ½ FAT