• 1/2 pound butter (2 sticks)
• 10 medium-sized sweet onions (like Vidalias), peeled and finely sliced
• 1/4 cup flour
• Stale bread crusts
• Salt
• 2 egg yolks, beaten
• 1/2 teaspoon vinegar

Melt butter in a large stew pan over medium-high heat. Add sliced onion and cook for 15 minutes, or until onions are tender. After that, stir occasionally until onions are dark mahogany and reduced to approximately 4 cups.

Shake in a little flour, and cook a few minutes longer. Add 4 cups water and stir. Take a piece of crust and throw it in the soup. Season to taste with salt. Turn heat on high, and bring soup to boil. Allow to boil for 10 minutes, stirring often. Take off the fire and have ready the beaten yolks, mixed with the vinegar. Mix some of the soup into the yolk-vinegar mixture, then stir back into the soup. Mix well.

Serves 10 to 12.

-- Adapted from "The Art of Cookery Made Plain and Easy" by Hannah Glasse