Home › The World's Kitchen › Onion Soup Au Gratin
Onion Soup Au Gratin
Prepare and strain a consomme into a bowl and keep hot. Cut three medium onions in halves and finely slice them. Heat an ounce butter in a saucepan, add the onions and brown for fifteen minutes, frequently stirring meanwhile. Then add three tablespoons flour and a saltspoon cayenne pepper; lightly mix, pour in the consomme, mix a little, then let gently simmer for thirty-five minutes. Transfer the soup into an earthen soup tureen and arrange six slices lightly toasted French bread on top. Dredge two ounces grated Parmesan, mixed with an ounce grated Swiss cheese, over all. Set in the oven to bake for fifteen minutes, remove and serve.
A standard soupe a l'oignon gratinee, written for a kitchen that already had consomme on hand. The quantities are workable as given, with two points needing attention: the amount of consomme is never stated, and the cayenne is far heavier than modern taste expects.
- The missing quantityNo volume of consomme is given. For three onions and three tablespoons of flour, work with 1.5 quarts (about 1.4 litres) of good beef or brown stock; that yields six portions matching the six slices of bread.
- Cut the cayenneA saltspoon is about a quarter teaspoon, which is aggressive in a mild onion soup. An eighth of a teaspoon is closer to modern palates, and the classic French version leans on black pepper instead.
- Browning is the hingeFifteen minutes over the heat will not truly caramelise three sliced onions. Give them 30 to 45 minutes over medium-low heat until deep golden brown; much of the sweetness and colour of the finished soup comes from this stage.
- The flourThree tablespoons gives a distinctly thickened, slightly velvety soup rather than the clear broth served in most restaurants today. Cook it with the onions for two minutes before the liquid goes in, or the soup tastes of raw flour.
- Oven heatNo temperature is given. Bake at 400F for the fifteen minutes specified, or run it under the broiler for three to four minutes if you only want the cheese browned and blistered.
- Tureen and crocksAn earthen soup tureen means a glazed earthenware vessel that can take oven heat. Individual ovenproof crocks are easier: they keep each portion's crust intact and shorten the baking time.
- Cheese proportionsTwo ounces Parmesan to one ounce Swiss (probably Gruyere or Emmental) is a sharp, salty ratio. Reversing it, or using Gruyere and Comte with a little Parmesan for bite, gives a stretchier crust.
- BreadUse day-old baguette cut about three-quarters of an inch thick and dried in the oven until crisp through, not just lightly toasted. Soft bread dissolves into the soup during baking.
Onion soup thickened with bread and browned with cheese is old peasant cookery given a restaurant finish; the gratineed version is popularly associated with the Paris market halls of Les Halles, where it was eaten by porters and by late-night diners, though the attribution is traditional rather than documented. The dish depends on cheap staples, onions and stale bread, plus one expensive element, good consomme, which is why it moved easily from a workman's meal to a hotel menu. The instruction to prepare and strain a consomme first assumes a household or professional kitchen with stock always going, a convenience that a good boxed or homemade beef stock now has to replace.