When I was a kid, I saw a movie called "Irma La Douce", a romantic comedy set in turn of the century Paris. One early scene depicted hordes of formally attired folks sitting around the tables of a greasy spoon cafe sipping hot bowls of French Onion Soup in the early morning. As a 14 year old I couldn't figure it out, but now I know. As Chef Jerry Pellegrino would agree, French Onion Soup is one of the great restoratives in the world.
Here's a breakdown of the dish.
1. Four simple components: the cooked onions, the broth, the crouton and the cheese. Of the four the cooking of the onions is the critical step.
2. We recommend sweet yellow onions for this recipe. And you'll want a heap of them, at least two large ones. Peel them, cut them in half top to bottom, then slice again lengthwise into long thin slices. You're going to slow cook the onions plus thyme sprigs and bay leaves in melted butter, which means you will keep the heat low. Use a Dutch oven, and keep stirring it up. Invest up to 45 minutes for this step.
You can also toss in a little brown sugar to move the process along. Eventually the onions will wilt down to a quarter of their original volume.
3. Next you will toss the cooked onions with flour, and add a little white wine.
Cook for a few more minutes then add your broth.
4. Beef broth is the traditional choice here, but chicken broth is OK. What you want, in any case, is concentrated, flavorful broth, so don't use anything watered down. Give the soup another 45 minutes or so, stirring occasionally.
5. As for the croutons, try slicing up a baguette, and toasting them in a warm oven. You can sprinkle a little seasoned salt on them for fun, or even better, rub a garlic clove on them.
6. For cheese, the standard choice is gruyere, although people often use parmesan sprinkled in. Have both thin slices and grated cheese available.
7. To serve, ladle out the soup into oven proof bowls (or big old coffee mugs), taking care to fish out the bay leaves and thyme sprigs. Top it with a layer of cheese, then float enough of the croutons to cover the top. Add a few strips of cheese on them, and then sprinkle a heap of the grated cheese on top, and slip the bowls under the broiler for about a minute or two...no more!
8. Julia Child suggested garnishing with a pinch of finely grated onion on the top, and to us that makes sense.