"Grilled Cheese" Burgers

Step 1

Preheat oven to 350°. Spread butter evenly on one side of each piece of bread, then place bread buttered side down in a cast-iron skillet over medium-high heat until golden brown. Transfer to a large sheet pan with toasted side down and place 2 pieces of American cheese on each piece of bread.

Step 2

Preheat same cast iron pan over high heat. In a mixing bowl, add cold ground beef and season with salt and pepper. Divide into 1/4-lb. burgers and form 1/2"-thick, square-shaped patties, similar to bread dimensions. (Avoid over-handling burgers as it will make them tough.) Cook burgers in two batches; flip burger after 2 minutes, then cook 2 minutes more. Transfer to a plate and loosely cover with aluminum foil; rest 2 minutes.

Step 3

Meanwhile, place sheet pan with bread in the oven until cheese is just melted. Lightly blot burgers with a paper towel, then place burgers on toasted bread with cheese and top with second piece of bread.

Step 4

Return grilled cheese burgers to the cast iron pan to warm the bread. Serve immediately, with ketchup.