Ingredients:
1 lb ground beef
1 large onion, thinly sliced
2 tablespoons butter
1 tablespoon olive oil
1 teaspoon sugar
1 teaspoon salt
1/2 teaspoon black pepper
4 slices Swiss cheese
4 burger buns
1/4 cup beef broth
2 tablespoons mayonnaise
2 tablespoons Dijon mustard
Fresh thyme leaves (for garnish)
Directions:
In a large skillet, heat butter and olive oil over medium heat. Add thinly sliced onions, sugar, and 1/2 teaspoon salt. Cook, stirring frequently, until the onions are caramelized and golden brown, about 20-25 minutes. Add beef broth and cook for an additional 5 minutes, until the liquid is mostly absorbed. Remove from heat and set aside.
In a large bowl, combine ground beef with remaining 1/2 teaspoon salt and black pepper. Mix until just combined and form into 4 equal patties.
Preheat a grill or skillet over medium-high heat. Cook the patties for 4-5 minutes per side, or until they reach your desired level of doneness.
During the last minute of cooking, place a slice of Swiss cheese on each patty and allow it to melt.
Toast the burger buns on the grill or in the skillet until lightly browned.
In a small bowl, mix mayonnaise and Dijon mustard. Spread the mixture on the toasted buns.
Assemble the burgers by placing the patties on the bottom buns, topping with caramelized onions, and adding fresh thyme leaves for garnish. Top with the remaining buns.
Prep Time: 15 minutes | Cooking Time: 30 minutes | Total Time: 45 minutes
Kcal: 550 kcal | Servings: 4 servings
