After years of experimentation and research, this is the best French onion soup recipe that I have come up with. It is an excellent dinner for guests because you can make it ahead of time and last-minute assembly doesn’t take very long. My secret to success is extra cheese: when I put the soup in the bowls, I do a layer of cheese, then bread, then lots more cheese.
Soupe à l’Onion Gratinée
makes 8 servings
4 tablespoons butter
8 onions, sliced
5 cloves garlic, crushed
5 sprigs thyme, tied together with kitchen twine
2 bay leaves
Sea salt and pepper
1 ½ cups sherry cooking wine
5 tablespoons flour
10-12 cups beef stock (my favorite brand is Kitchen Basics)
A bunch of gruyere (I think I used about 4 cups…)
I baguette, cut into slices
8 oven proof bowls
Melt the butter in a large soup pot. Add the onions, sprinkle with about 1 tablespoon of sea salt and stir over high heat until they begin to release their liquid. Add the garlic , thyme, and bay leaves. Reduce the heat to medium and let the onions caramelize, stirring occasionally, until they become dark brown, about 15-20 minutes (the longer the better).
Turn the heat up to high and add the sherry, scraping the bottom of the pan to deglaze. Stir the until the wine evaporates then sprinkle with the flour. Add the beef stock and bring to a boil. Reduce heat and let simmer for 1-2 hours. At this point, the soup can be refrigerated and kept for 1-2 days- this actually helps the flavors of the soup combine for a tastier result.
When ready to serve, bring the soup to a boil on the stove and preheat the broiler. Fish out the thyme and bay leaves. Taste soup and season accordingly (it probably won’t need any salt). Distribute the soup among 8 oven-proof bowls. Top with some cheese, then two slices of bread, then more cheese. Broil until the cheese becomes bubbly and brown. Serve with extra bread for dipping.