To a large pan on the stove, add in the ground beef and onion break the ground beef up and cook it through.
Remove any excess grease from the pan, stir in the relish, mustard, mayonnaise, and ketchup Slice the dinner rolls in half horizontally, then place on a sheet pan place the slices of cheese on both sides of the rolls, then place the hamburger mixture on one side of the rolls, place the top of the rolls on the hamburger mixture and set to the side.
To a small bowl, add in the melted butter and sesame seeds. Stir well. Brush this on top of the rolls. Bake for 5 to 8 minutes.