This is the best Homemade French Onion Soup! It has a generous portion of caramelized onions in a rich, flavorful beef broth made from scratch. Three types of cheese are broiled on top of croutons to melty, toasty perfection.
Everyone knows that the three key ingredients in French cuisine are butter, butter, and butter, but I would argue that there is a fourth. That secret is high quality ingredients. Real cream, quality cheese, fresh, in-season produce, and, of course, butter.
French Onion Soup, at its core, is a very simple soup. It is here that quality ingredients matter.
If you want to turn a good soup into a tantalizing culinary experience, you need to start with homemade beef broth. I’m talkin’ roasted veal and beef bones simmering for hours. Try it. Then you’ll understand.
You will want to make sure that your onions are deliciously caramelized. Almost more than you think is right. Even darker than the pictures in my initial post. They will smell sweet with a note of caramel, and should be a rich caramel brown.
My secret in this recipe? Cognac. There are only 2 tablespoons in 4 servings but this is the flavor that pulls the onions and broth and cheese together and makes a symphony of taste. It is the flavor that your guests won’t quite be able to pinpoint, but they will know there is something truly delightful and different about your French Onion Soup. Cognac.
Gruyere cheese is traditional and you would not be remiss using all gruyere, but I used a medley of gruyere, Swiss, and fontina and it was delicious.
Dig through the cheese and the bread with your spoon and scoop up some of the broth and onions into one complete bite. Marvel as your eyes close and you sigh in pleasure. It is seriously that delicious. Simple done right.
That is what home cooking is all about, right?
I didn’t need an excessive amount of salt in this soup, and that is how I wrote it below. Sometimes salt is a flavor enhancer and sometimes it is compensating for a lack of flavor development. Many a restaurant French onion soup is suffering from this disorder. Sad but true.
The Best Homemade French Onion Soup
- 1 cup caramelized onions
- 1 tablespoon flour
- 1 tablespoon chopped fresh thyme (not packed)
- 2 tablespoons Cognac*
- 3 ½ cups beef broth (Preferably homemade or organic low-sodium)
- Kosher salt and fresh cracked black pepper (to taste)
- 1 French baguette (sliced ¾ inch thick along a diagonal)
- 1 ½ cups gruyere (swiss and fontina cheese**)
- When making French onion soup, I caramelize my onions in a Dutch oven, so that I only dirty one pot. L-A-Z-Y
- Once your onions are sufficiently caramelized (deep, rich caramel in color) sprinkle with the flour and stir to coat. Add the thyme, Cognac, two large pinches kosher salt and a few grinds of pepper. Stir to distribute the spices and allow to cook on low for a few minutes.
- Add your beef broth and simmer over low heat for 30-40 minutes. This allows the flavors to develop.
- While your soup is simmering, toast your bread on a baking sheet under the broiler. Watch it carefully! Toast until brown on each side.
- Ladle an equal amount of soup into each broiler-safe, 13 ounce bowl. Top with several bread slices and then top with ¼ of the cheese mixture. Broil on a baking sheet until the cheese has melted and has started to bubble and brown.
- Serve immediately, but eat with care! HOT!