French Onion Soup Recipe
Gratin with gruyere cheese
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Ingredients
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Onion soup
Gratin / garnish
Method
Onion soup
- 1
Prepare onions
Peel the onions and slice them thinly into half-moons (about 1/8–1/4 inch / 3–6 mm thick). Aim for even slices so they caramelize uniformly.
- 2
Caramelize onions
In a large heavy-bottomed pot or Dutch oven, heat butter and olive oil over medium heat until butter melts and foams. Add the sliced onions, sprinkle with kosher salt and granulated sugar. Cook, stirring every few minutes, for 25–35 minutes until onions are deep golden-brown and very soft. Adjust heat to medium-low if onions begin to brown too quickly on the edges. Scrape browned fond from the bottom occasionally to encourage even caramelization.
- 3
Deglaze
Raise heat to medium-high, add the white wine (or sherry) to deglaze the pan. Scrape all browned bits from the bottom with a wooden spoon, and let the liquid reduce by half (1–2 minutes).
- 4
Simmer soup
Add the beef stock, bay leaves, thyme, Worcestershire sauce, and freshly ground black pepper. Bring to a gentle simmer, then reduce heat and simmer uncovered for 20–25 minutes to meld flavors. Taste and adjust seasoning with salt and the sherry or red wine vinegar to brighten the soup. Remove bay leaves before serving.
Gratin / garnish
- 5
Prepare bread slices
While the soup simmers, preheat the oven to 400°F (200°C). Arrange the baguette slices on a baking sheet, brush lightly with extra-virgin olive oil, and toast in the oven 6–8 minutes until lightly crisp and golden. Rub each warm toast with the cut side of the garlic clove for a hint of garlic flavor.
- 6
- 7
Grill to gratin
Place the filled bowls on a baking sheet and transfer to the oven. Broil on high (or use the oven’s broiler) about 3–6 minutes, watching closely, until the cheese is melted, bubbling, and golden-brown in spots. Rotate the tray if needed for even browning. Remove carefully with oven mitts.
- 8