PREPARATION:

1. Preheat oven to 425°F. Combine flour, cornmeal, baking powder, sugar, salt and baking soda in large bowl; mix well. Cut in margarine with pastry blender or two knives until mixture forms coarse crumbs. Add buttermilk; mix just until dough holds together.
2. Turn dough out onto lightly floured surface; knead 8 to 10 times. Pat dough to 1/2-inch thickness; cut with decorative 2-inch cookie or biscuit cutter. Spray baking sheet with nonstick cooking spray and place biscuits on sheet. Brush tops lightly with beaten egg white.
3. Bake 12 to 13 minutes or until light golden brown. Serve with preserves, if desired.