Onion Soup - cooking recipe

Ingredients

3 Tbsp. butter
3 large onions, sliced thin
1 Tbsp. flour
1/2 tsp. salt
fresh ground black pepper
5 c. beef broth
4 thick slices French bread
4 Tbsp. Parmesan cheese, grated
4 Tbsp. Swiss cheese, grated

Preparation

In heavy pan, melt butter.
Add onions and cook slowly, stirring occasionally, until golden.
Sprinkle on flour and stir a few minutes to cook the flour.
Season with salt and pepper.
Add in broth, stirring constantly.
Bring to a boil.
Lower heat and let simmer, partially covered, for 30 minutes.