Grilled Onion & Swiss Cheeseburger
Prep Time: 5 minutes
Cook Time: 20 minutes
Total Time: 25 minutes
Preheat a greased grill to medium heat.
In a bowl, toss sliced onions with olive oil, salt and pepper.
Cook onion on grill until they are softened and browned, stirring often, about 10 minutes. Set onions aside while you grill the beef patties.
Cook beef patties until charred and fully cooked through, about 4-5 minutes per side. Adjust grill temperature as needed. Internal temperature should register 160°F on an instant read thermometer.
Top beef patties with Swiss cheese during the last minute of cooking.
To assemble burgers, add mayonnaise and mustard to buns and fill with lettuce, beef patties with cheese, and grilled onions.
Serve burgers immediately.