Onion Soup Au Gratin - cooking recipe

Ingredients

1/2 c. margarine or butter (1 stick)
1 1/2 c. thinly sliced onions
1/2 c. flour
1 egg yolk
2 Tbsp. light cream
2 (13 3/4 oz.) cans beef broth
1 1/2 tsp. salt
dash of cayenne
4 thin slices French bread
1/2 c. Parmesan cheese

Preparation

Saute onions in melted butter until soft.
Blend in flour and cook for 5 minutes, stirring constantly.
Stir in broth, salt and cayenne.
Heat to boiling, stirring constantly.
Lower heat; simmer 15 minutes.
Beat egg yolk and cream in small bowl.
Blend in about 1 cup of the hot soup.
Stir mixture in saucepan.
Ladle soup into 4 individual flame-proof bowls.
Float a slice of French bread on each and top with Parmesan cheese.
Broil, watching carefully, 4 inches from heat until cheese turns golden.