Soup à l’Oignon Gratinée

• 6 medium-sized onions
• 3 tablespoons butter
• 3 tablespoons

Peel and slice onions thinly. Heat butter and olive oil in a large saucepan with a little sugar; add the onion rings and cook them very, very gently over a low heat, stirring constantly with a wooden spoon, until the rings are an even golden brown. Add beef stock gradually, stirring constantly until