Grilled Patty Melts

Preheat an outdoor grill for medium heat and lightly oil the grate.

Pat out three 1/3-pound hamburger patties, pressing each patty down with your index and middle fingers to get a nice, flat burger instead of a ball. Season patties on both sides with salt and pepper.

Cook on the preheated grill until no longer pink in the centers, 10 to 12 minutes, flipping halfway. An instant-read thermometer inserted into the center should read at least 160 degrees F (70 degrees C).

Meanwhile, melt butter in a saucepan over low heat. Increase heat to medium-low, add onion, and saute until tender, 5 to 7 minutes.

Place 3 slices of bread on the grill. Top each with a slice of American cheese, a cooked patty, sauteed onions, a slice of Swiss cheese, and the remaining bread. Grill sandwiches until cheese melts, about 1 minute per side.