Name: Hearty Lentil French Onion Soup With Melty Gruyère
Prep time: 25 min
Cook time: 1 h 30 min
Total time: 1 h 55 min
Yield: 4
Cuisine: American
Ingredients: 4 tablespoons (57 g) unsalted butter, plus more for bread; 2 pounds (900 g) yellow onions, thinly sliced (about 7 cups; see notes); 1 1/2 teaspoons Diamond Crystal kosher salt, plus more to taste; for table salt, use half as much by volume; 1/2 teaspoon freshly ground black pepper; 1/4 cup (120 ml) dry sherry; 7 cups (1.65 L) homemade beef stock or homemade or store-bought low-sodium chicken stock; 1 cup dried French le Puy lentils (7 ounces; 200 g), picked over for stones, rinsed, and drained; 2 fresh thyme sprigs, plus thyme leaves for garnish; 1 dried bay leaf; 1 teaspoon (5 ml) apple cider vinegar; 8 (1/2-inch-thick) French bread slices, trimmed to fit bowl size, and toasted until crisp; 1 medium clove garlic; 8 ounces (226 g) Gruyère cheese, grated (about 2 cups)

Hearty Lentil French Onion Soup With Melty Gruyère

Lentil soup meets French onion soup in this hearty winter mashup with deeply caramelized onions and molten Gruyère cheese.

1 hr 55 min total 25 min prep 1 hr 30 min cook 4 784 cal

Instructions

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1 In a large Dutch oven, melt butter over medium-high heat until foaming. Add onions, salt, and pepper; cook, stirring occasionally, until onions are softened, 6 to 8 minutes.
2 Reduce heat to medium-low and cook, stirring frequently and scraping bottom of pot as needed, until onions are sweet and deeply caramelized, 45 minutes to 1 hour. If browned onion juices on bottom of pot threaten to burn, add 1 tablespoon (15 ml) water, scrape up browned bits, and continue cooking.
3 Add sherry, scraping up any browned bits, and cook over medium until alcohol is mostly evaporated, 2 to 3 minutes.
4 Add stock or broth, lentils, thyme sprigs, and bay leaf. Bring to a boil over medium-high heat, then reduce heat to medium-low, cover, and simmer, stirring occasionally, until lentils are tender but hold their shape, 25 to 30 minutes.
5 Remove and discard thyme sprigs and bay leaf. Stir in apple cider vinegar. Season with additional salt and pepper to taste.
6 Preheat broiler and adjust oven rack to about 6 inches from heat source. Lightly butter toasted French bread slices, and rub with garlic clove until fragrant.
7 Ladle soup evenly into 4 broiler-safe bowls. Top each bowl with 2 slices of bread, overlapping slightly. Sprinkle each bowl evenly with 1/2 cup (2 ounces) Gruyère cheese.
8 Place bowls on a rimmed baking sheet. Broil until cheese is melted and browned in spots, about 3 to 4 minutes. Garnish with thyme leaves, and serve immediately.