- 1 pound lean ground beef
- 2 tablespoons dried minced onion
- 1 (12 ounce) bottle chili sauce (such as Heinz)
- 2 ½ tablespoons brown sugar
- 1 tablespoon water, or as needed
- ½ cup salted butter, softened, or as needed
- 16 slices bread
- 16 slices American cheese
Heat a large skillet over medium-high heat. Cook and stir ground beef and minced in the hot skillet until browned and crumbly, 5 to 7 minutes.
Add chili sauce and brown sugar. Rinse chili sauce jar with water to get the remnants of the sauce; add to the beef mixture. Stir, reduce heat, and simmer for 10 to 15 minutes. Remove from the heat.
Butter one side of 2 slices of bread. Place one slice, butter-side down, in a new skillet over medium heat. Layer with 1 slice of American cheese, a scoop of Sloppy Joe mixture, another slice of cheese, and the second piece of bread, butter-side up. Cook until sandwich is browned on the bottom and the bottom slice of cheese is melted, 3 to 5 minutes. Flip sandwich over and repeat on the other side. Repeat to assemble and cook remaining sandwiches.