French Onion Soup

Yield: 1 Servings
3tbUnsalted butter
1 1/2lb(4 large) Bermuda onions, spanish onions, or sweet onions of your choice, thinly sliced
1cDry white wine
2qtBeef broth (see note below for using canned)
2Ribs celery with leaves, each rib cut in half
Salt to taste (remember that the broth may be salty, and that you will be topping the bowls with cheese ... I, myself, would just omit this, but YMMV)
Black pepper to taste
1/4cDry fino sherry
4slFrench bread, each cut 1/4-inch thick and lightly toasted (up to 6)
1/4cCoarsely grated Emmenthal, Gruyere, or other Swiss-type cheese (up to 1/3)