1. Have melt the butter over moderate heat in a large heavy stockpot or Dutch oven. Add the onions, season with salt and pepper and cook until soft but not colored, 15 minutes.
2. can cut the bread into medium dice and add it to the pot along with the sugar. Stir constantly for about 1 minute, so the bread absorbs the butter.
3. Add the chicken stock and bring to a boil. Simmer for 20 minutes. can add the cheese slowly. Stirring can be a . Reduce to a low simmer. Cook, uncovered, stirring occasionally, about 10 minutes.
4. Meanwhile heat the milk in the microwave until it is steaming. Slowly stir it into the pot. (Note: Do not let the soup boil or the cheese will separate and the milk will curdle.) Serve immediately.Serving Size: 1 bowl