French Onion Soup - cooking recipe

Ingredients

6 onions, shredded or sliced
4 Tbsp. butter
4 c. chicken stock (broth)
2 c. beef broth
3 or more slices dry French bread
1 plus c. shredded mild Swiss cheese
fresh grated Parmesan cheese (optional)

Preparation

Melt the butter in a large heavy saucepan and saute the onions over a low heat, stirring frequently, 20 to 30 minutes.
Increase the heat, stir and saute the onions until they are golden brown. Add the broths and simmer 20 minutes.