6 oz. onions, thinly sliced
2 Tbsp. butter
2 level Tbsp. flour
5 c. beef stock
salt to taste
pepper to taste
Mozzarella or Swiss cheese

Sauté the onions in the butter for a moment. Sprinkle them with the flour and as soon as they start to brown, stir in the stock. Add salt and pepper to taste and cook for about 20 minutes.

Put grated cheese in bottom of serving bowls and serve.