Heat a large nonstick skillet over medium-high heat. Fry the salami until it begins to get crisp and render some fat, 2 to 3 minutes; flip it and top with 2 slices of havarti. Cook until the cheese melts, 2 to 3 minutes. Remove from the pan and quarter each piece; set aside. Repeat the process with the mortadella and the remaining cheese.
Smear the rolls with the mustard. Layer a slice each of fried salami and mortadella, some pickles and a few potato chips on the rolls.