1 1/2 c. butter
4 c. sliced white onions
3/4 c. flour
12 c. beef stock
1/2 tsp. cayenne pepper
Salt to taste
1 egg yolk
2 tbsp. cream

Cook onion in butter until tender. Add flour and cook 5 to 10 minutes. Blend in stock, salt, and pepper; beat egg yolk and cream with a little soup stock and add to mixture. Simmer until ready to serve. Toast bread and break into soup with Parmesan cheese or Mozzarella - or both. (Use 12 cups water and abut 14 to 16 bouillon cubes to make beef stock.)