I like to mix in some onion soup mix (what you use to make chip dip.. it's SO good) and then top with a variety of cheeses . I use Kaiser buns for my burgers, much better than potato bread
I top with imported gorgonzola and serve on a lightly toasted kaiser roll with a slice of red onion, lettuce, fresh tomato and s&p. No condiments. Fries, pickle and a margherita on the side.