Cook the onions slowly with the butter and oil in the covered saucepan for 15 minutes. Uncover, raise heat to moderate, and stir in the salt and sugar. Cook for 30 to 40 minutes stirring frequently, until the onions have turned an even, deep, golden brown. Sprinkle in the flour and stir for 3 minutes.

Off heat, blend in the boiling liquid. Add the wine, and season to taste. Simmer partially covered for 30 to 40 minutes or more, skimming occasionally. Correct seasoning.

Set aside uncovered until ready to serve. Then reheat to the simmer.

Just before serving, stir in the cognac. Pour into a soup tureen or soup cups over the rounds of bread, and pass the cheese separately.

Garnishings for Onion Soup (Croûtes-Hard-Toasted French Bread)

12 to 16 slices of French bread cut ¾ to 1 inch thick

Olive oil or beef drippings

A cut clove of garlic

Place the bread in one layer in a roasting pan and bake in a preheated 325-degree oven for about half an hour, until it is thoroughly dried out and lightly browned. Halfway through the baking, each side may be basted with a teaspoon of olive oil or beef drippings; and after baking, each piece may be rubbed with cut garlic.

Croûtes au Fromage (Cheese Croûtes)

Grated Swiss or Parmesan cheese

Olive oil or beef drippings

Spread one side of each croûte with grated cheese and sprinkle with drops of olive oil or beef drippings. Brown under a hot broiler before serving.

VARIATIONS:

Soupe à l’Oignon Gratinee (Onion Soup Gratineed with Cheese)

The preceding onion soup

A fireproof tureen or casserole or individual onion soup pots

2 ounces Swiss cheese cut into very thin slivers

1 Tb grated raw onion

12 to 16 rounds of hard toasted French bread

1½ cups grated Swiss, or Swiss and Parmesan cheese

1 Tb olive oil or melted butter

Preheat oven to 325 degrees. Bring the soup to the boil and pour into the tureen or soup pots. Stir in the slivered cheese and grated onion. Float the rounds of toast on top of the soup, and spread the grated cheese over it. Sprinkle with the oil or butter. Bake for 20 minutes in the oven, then set for a minute or two under a preheated broiler to brown the top lightly. Serve immediately.

Soupe Gratinee des Trois Gourmandes (Onion Soup Gratineed de Luxe)

A final fillip to the preceding onion soup may be accomplished in the kitchen just before serving or by the server at the table.

A 2-quart bowl

1 tsp cornstarch

1 egg yolk

1 tsp Worcestershire sauce

3 Tb cognac

The preceding onion soup

A soup ladle

A serving fork

Beat the cornstarch into the egg yolk, then the Worcestershire and the cognac.

Just before serving the soup, lift up an edge of the crust with a fork and remove a ladleful of soup. In a thin stream of droplets, beat the soup into the egg yolk mixture with a fork. Gradually beat in two more ladlefuls, which may be added more rapidly. Again lifting up the crust, pour the mixture back into the soup. Then reach in under the crust with the ladle and stir gently to blend the mixture into the rest of the soup. Serve.