INGREDIENTS:
1 lb ground beef
2 large onions, thinly sliced
2 tablespoons butter
1 teaspoon sugar
1/2 cup beef broth
2 tablespoons Worcestershire sauce
1 teaspoon fresh thyme leaves (or 1/2 teaspoon dried thyme)
Salt and pepper to taste
4 slices of Gruyère or Swiss cheese
4 hamburger buns
1 clove garlic, minced (optional for garlic butter buns)
Additional butter for buns
DIRECTIONS:
Caramelize the Onions:
In a large skillet over medium heat, melt the butter.
Add the sliced onions and sugar.
Cook, stirring occasionally, until the onions are deeply caramelized and sweet, about 20-25 minutes.
Add a splash of beef broth if the onions start to stick, to deglaze the pan.
Prepare the Burger Patties:
Season the ground beef with salt, pepper, and Worcestershire sauce.
Form into 4 equal-sized patties.
In a separate skillet or on a grill, cook the burger patties to your desired level of doneness.
Assemble the Burgers:
If desired, prepare garlic butter buns by spreading buns with a mixture of butter and minced garlic, then toasting until golden.
On each bun bottom, place a cooked burger patty.
Top each patty with a generous helping of caramelized onions and a slice of cheese.
Broil the assembled burgers for a few minutes until the cheese is melted and bubbly.
Sprinkle fresh thyme over the cheese, cover with bun tops, and serve immediately.
Prep Time: 15 minutes | Cooking Time: 30 minutes | Total Time: 45 minutes
Calories: 650 kcal per burger | Servings: 4 servings