Preheat oven to 425 degrees Fry diced onion in butter until caramelized, about 15 to 20 minutes.
Combine cooled onions, flour, baking powder, salt and pepper. Rub in vegetable shortening or butter. Mix in 1/2 cup milk. Gently knead dough. Pat out to a 1-inch thickness.
Cut into round or square biscuits. Place in a greased 9-inch pan so that they touch. Brush melted butter over. Bake until well browned, about 20 minutes.
Serve with BLACK BEAN SOUP