Score the edges of the pork roll slices in 3 or 4 places. This will keep the slices flat and prevent them from buckling as they cook.
Heat the butter in a large nonstick skillet over medium-high heat. Add the pork slices in one layer and brown well on both sides, about 6 minutes. Remove the slices and place one on top of each toasted roll bottom.
Reduce the heat to medium-low and crack the eggs into the skillet. Break each yolk with the corner of your spatula. Sprinkle with salt and pepper. After about 2 minutes, flip the eggs and continue cooking on the other side. Immediately place a slice of American cheese on top of each egg. Cover with a lid to melt the cheese, about 30 seconds.
Place each egg and cheese quadrant on top of a browned pork roll slice. At this point you can squeeze ketchup on top if desired. Top with the other half of the roll.
Recipe courtesy of Young Sun Huh for Cooking Channel