French onion soup is one of those things people love ordering at a restaurant because they don’t make it at home. There’s a certain mystique about this bistro classic: that cheesy topping, the floating toasts, the melt-in-your mouth onions. No way you could create something that delicious in your own kitchen.
Way (pardon my lame Wayne’s World reference). French onion soup is (1) simple and (2) inexpensive. A whole batch costs nearly the same as one bowl at a restaurant – about £4 or $7.
The key to perfect french onion soup is a long, slow cooking time. The prep takes about 5 minutes – just slicing some onions (slicing, so much simpler than chopping) – then they do their own thing on the stove for the next hour and a half, with occasional intervention on your part.
The cheesy toasted topping tends to intimidate as well. Especially if you don’t have oven-safe soup bowls.
Even if you do, removing broiling-hot bowls from the oven and then every two minutes reminding your soup eaters “do NOT touch the bowl” isn’t my idea of a relaxing dinner.
That rigmarole is eliminated with cheesy toasts: baked separately then floated on top of the soup. Use any bowl you wish. You can even bake the toasts ahead of time and still have that cheesy goodness (I usually bake them during the final 10 minutes of the soup’s cooking time).
French Onion Soup (serves 4-6)
Note: For the best tasting soup, use the maximum cooking times suggested below. Trust me, the longer the better! If using beef stock cubes, use double the recommended amount of water per cube. I used 1 cube per liter, whereas the package said to use 1 cube per 450 ml (broth will taste a bit watered down, but as it cooks for 30-40 minutes it will reduce and gain more flavor without being overly salty).
1 1/2 lbs (680 grams) yellow onions, cut in half and thinly sliced (about 3-4 onions, 5 cups sliced)
3 tablespoons (42 grams) butter
1 tablespoon olive oil
1 teaspoon salt
1/4 teaspoon sugar
3 tablespoons flour
8 cups (2 liters) boiling beef stock (see Note above)
1/2 cup (120 ml) dry white wine, dry white vermouth, or dry sherry
Salt and pepper to taste
1 cup (120 grams) grated Gruyère or Swiss cheese
Place onions, butter and olive oil in a Dutch oven or large (4-5 quart / 5 liter saucepan), cover, and cook slowly over low heat for 15 minutes. (I used a 7-quart Le Creuset just because that’s what size I have and I love using it for everything! But you don’t need to use something that big – 5 quart or 5 liter is plenty big).
Uncover, raise heat to medium, and stir in the salt and sugar. Cook for 30 to 40 minutes stirring occasionally (every 5-10 minutes), until the onions have turned an even, deep, golden brown. Turn heat down a bit if onions start to burn.
Preheat oven to 350°F / 175°C. Sprinkle in the flour and stir for 2-3 minutes. Off heat, blend in the boiling stock, scraping up any brown bits from the bottom of the pan. Add the wine and season to taste. Simmer partially covered for 30 to 40 minutes or more.
While simmering, cut baguette into 3/4” (2 cm) to 1” (2 1/2 cm) thick slices (allow 2-3 slices per bowl of soup). Place bread in a single layer on a rimmed baking sheet and bake until dried out and slightly browned, about 5 minutes. Remove from oven and sprinkle bread with grated cheese. Put back in oven and bake until cheese is melted, about 3-4 minutes. If you prefer your cheese lightly browned on the top, place under the broiler for a few minutes.
Ladle soup into bowls. Place 2-3 cheesy toasts atop each bowl.
Adapted from “Mastering the Art of French Cooking” by Julia Child