French Onion Soup Burger
Gilded with toasty cheese and loaded with sweet caramelized onions, French onion soup is a classic pairing of beefy flavors and savory curds. Here, we’ve turned the appetizer into a main dish.
Ingredients
- 1 tablespoon unsalted butter
- 2 yellow onions sliced
- 1 tablespoon red wine or beef stock
- Kosher salt to taste
- 1 pound ground beef
- 1 tablespoon soy sauce
- 1 tablespoon Worcestershire sauce
- Ground black pepper to taste
- 6 ounces Gruyère cheese grated
- 4 crusty burger buns
- 4 tablespoons mayonnaise
Instructions
- Melt butter in a large skillet over medium heat. Add onions and stir to coat. Cook, stirring occasionally, until darkened and collapsed, about 30 minutes, reducing heat as necessary to prevent burning. Add red wine and stir, scraping up any browned bits from bottom of the pan. Salt onions to taste and set aside.
- Using your hands, combine beef, soy sauce, and Worcestershire sauce in a bowl. Divide beef mixture into 4 mounds and flatten into ¹/³-inch-thick patties (about 5 inches in diameter).
- Heat a cast-iron skillet over medium-high. Season both sides of patties with salt and pepper, then cook for 3 minutes, pressing to flatten. Reduce heat to medium, flip, and top patties with Gruyère. Cover and cook 2 minutes more. Meanwhile, toast buns.
- Spread 1 tablespoon mayonnaise on each bun bottom. Top with 1 burger patty and a pile of caramelized onions. Close burgers with top halves. Serve immediately.