In an electric frying pan, sauté 5 C. of onions. Add 2 tsp. of minced garlic and 1 T. of water. Stir in 1 tsp. of Splenda and 1 tsp. of flour. Add 5 C. of low sodium beef stock or broth and stir. Pour the soup into individual oven-proof soup bowls. Toast 2 slices of whole wheat bread, cut off the crusts and add them to the top of each soup bowl. Now sprinkle 1/2 C. of light cheddar cheese and 1/2 C. of light mozzarella cheese over the toast and broil until the cheese has just melted.