A bowl of French Onion Soup is timeless comfort at its best—slowly caramelized onions simmered in a savory broth, finished with crusty baguette and bubbling cheese. This version sticks to classic technique and simple ingredients, delivering a cozy, restaurant-worthy result right at home.
Caramelizing Onions
Caramelizing onions is the heart of French Onion Soup—and it’s worth every minute. I use a mandoline to quickly create thin, uniform slices, which ensures even cooking and helps the onions break down beautifully.
While it might be tempting to rush this step, true caramelization takes time—at least 40 minutes of slow cooking over medium heat. As the onions cook, their natural sugars develop into rich, deep flavor and golden color.
Cheese: the Star of French Onion Soup
When it comes to French Onion Soup, the cheese is just as important as the broth. You want something that melts beautifully, browns well under the broiler, and adds a touch of indulgence to every bite.
Gruyère is the classic pick—nutty, rich, and perfectly stretchy.
Swiss cheese is a great alternative with a slightly milder flavor, but still offers that satisfying melt. For a sharper bite.
Can’t choose? Do what I do and use a blend.
Notes From the Kitchen
Dry Whites: Choose a dry white wine like Sauvignon Blanc, Pinot Grigio, or a dry Chardonnay. These wines add brightness and acidity that balance the sweetness of the caramelized onions and deepen the broth’s flavor. Skip anything sweet—crisp and dry is the move here.
Low and Slow: Watch your stove temps. If the onions start sticking, lower the heat and keep going.
French Onion Soup
Equipment
- 1 Mandolin optional
- 1 Dutch Oven (or other heavy pot)
Ingredients
- 5-6 Yellow Onions (large)
- 4 tbsp butter
- 4 cloves garlic, minced
- 3 tbsp all-purpose flour
- ½ cup dry white wine
- 6 cups beef stock
- 1 tsp Worcestershire sauce
- 2 bay leaves
- 3 sprigs fresh thyme
- 1 baguette, sliced
- Grated cheese (Gruyère, Swiss, or a blend)
Instructions
- Using a mandolin slide your onions into thin slices.
- In a large Dutch oven, melt the butter over medium heat. Add the sliced onions and a generous pinch of salt. Cook, stirring frequently, for 40–50 minutes, until the onions are deeply golden and caramelized.
- Stir in the minced garlic and cook for 1 minute. Sprinkle in the flour and cook for 2–3 minutes, stirring constantly to create a light roux.
- Pour in the white wine, scraping up any browned bits from the bottom of the pot. Simmer for a few minutes until slightly reduced.
- Add the beef stock, Worcestershire sauce, bay leaves, and thyme. Bring to a simmer and cook uncovered for 20–30 minutes. Season to taste with salt and freshly-cracked black pepper. Remove bay leaves and thyme sprigs before serving.
- While the soup simmers, preheat your oven’s broiler. Toast the baguette slices until golden. Set aside.
- Ladle the hot soup into oven-safe bowls. Place a slice of toasted baguette on top of each and generously cover with grated cheese. Place bowls under the broiler until the cheese is melted and bubbling, about 2–3 minutes. Watch closely!
