3 tablespoons bacon drippings (4 bacon strips)
6 Maui or Vidalia onions (3 pounds/8 cups), thinly sliced
2 large shallots, chopped
1 tablespoon balsamic vinegar
1 cup burgundy wine
2 teaspoons dried oregano
3 quarts chicken broth
Salt and freshly ground black pepper, to taste
Sliced baquette, toasted and seasoned
Swiss cheese, grated
Flat-leaf parsley, chopped, for garnish

In a large saucepan over medium heat, fry 4 strips of bacon until crisp.
Discard bacon. Saute onions and shallots in bacon fat until tender, about 10 minutes.
Add balsamic vinegar, wine and oregano; cook for 30 minutes.
Stir frequently until the onions caramelize and are golden brown. Blend in chicken broth. Simmer gently for 1 hour, stir occasionally.
Season with salt and pepper. Ladle soup into 4 ovenproof bowls.
Float the croutons on top of soup and sprinkle with grated cheese.
Broil until cheese melts.
Garnish with flat-leaf parsley, serve immediately.