1Melt 4 tablespoons of unsalted butter over medium-high heat.
2Add in 5 large yellow onions that are thinly sliced and cut into half moons.
3Sauté the onions, stirring often, for about 10 minutes until they are softened.
4Turn down the heat to medium.
5Add in 1 teaspoon of salt and 1 teaspoon of sugar and stir.
6Continue to cook the onions for another 35 minutes, stirring every 5 minutes, until they are caramelized and almost syrupy.
7Add in two cloves of minced garlic and sauté until fragrant.
8Add in half a cup of dry red wine to deglaze the pot, scraping up any brown bits.
9Add in 32 ounces of low sodium beef broth, 24 ounces of low sodium chicken broth, 1 tablespoon of Worcestershire sauce, two sprigs of fresh thyme, and one dried bay leaf.
10Let the soup gently simmer for about 20 minutes, stirring occasionally.
11Remove the herbs from the soup.
12Add in half a tablespoon of balsamic vinegar and a little bit of salt and pepper, then stir.
13Keep the soup warm while preparing the bread.
14Arrange five 1-inch thick slices of French bread on a baking sheet and baste both sides with olive oil.
15Preheat your broiler to high with the rack 6 inches from the heat source.
16Broil the bread for 2 to 3 minutes, flipping once, and keep an eye on them to prevent burning.
17Arrange five oven-safe bowls or crocks on a rimmed baking sheet.
18Fill the bowls 2/3 of the way full with the hot soup.
19Place one toasted bread slice on top of each bowl of soup.
20Sprinkle with freshly shredded Gruyère cheese, mozzarella cheese, and freshly shredded Parmesan cheese.
21Broil the bowls until the cheese is melted and golden.
Ingredients
4 tbsp unsalted butter
5 large yellow onions, thinly sliced and cut into half moons
1 tsp salt
1 tsp sugar
2 cloves minced garlic
0.5 cup dry red wine like a Cabernet or a Merlot or a Pinot
32 oz low sodium beef broth
24 oz low sodium chicken broth
1 tbsp Worcestershire sauce
2 sprigs fresh thyme
1 dried bay leaf
0.5 tbsp balsamic vinegar
salt
pepper
5 1-inch thick slices of French bread
olive oil
freshly shredded Gruyère cheese
mozzarella cheese
freshly shredded Parmesan cheese
Equipment
baking sheetoven-safe bowls or crocksrimmed baking sheetbroiler
Tips
The key to a really great French onion soup is the broth and the caramelized onions.
If you don't cook with alcohol, you can omit the red wine, but the flavor won't be as rich.
Keep an eye on the bread while broiling so it doesn't burn.