MELT BUTTER IN A 2-QUART POT over medium heat on the stove. Add the onions and cook covered, stirring occasionally, for 10 minutes or until onions are soft. Add the mushrooms, replace the cover and continue to cook another 10 minutes. Add the sherry, thyme, salt and pepper. Sprinkle the onion/mushroom mixture with flour and cook, stirring, about a minute. Add the milk and cream, cover and simmer 10 minutes more. Do not let the soup come to a rolling boil or the milk will curdle. Serve the piping hot soup immediately. MICHAEL ROBERTS PRODIGY GUEST CHEFS COOKBOOK