Recipe: French Onion Soup (crock pot)

French Onion Soup

1 quart beef bouillon or brown stock
3 medium yellow onions, thinly sliced
3 tablespoons butter
1/2 teaspoon salt
1 tablespoon sugar
2 tablespoons flour
1/4 cup dry vermouth or cognac (optional)
1 cup grated Parmesan cheese (I use a slice of Provolone cheese)

Pour bouillon or stock in stoneware. Cook onions slowly in butter (about 15 minutes) in large covered skillet. Stir occasionally. Uncover and add salt, sugar, flour and vermouth. Stir well. Add to stock in slow cooker. Cover and cook on Low 6 to 8 hours. (High: 3 hours). Before serving, top with grated cheese.