Curling, also known as buckling, is when the edges of a steak or pork chop start to curl up, resulting in uneven cooking. When the fat band around the outside of the meat gets hot, it begins to render and loses moisture rapidly.
Cook’s Country explains that this issue is common with thinner-cut pork chops, which don't have enough heft to keep themselves as flat as thicker ones. Fortunately, there is an easy fix for buckling that grillmasters and pan-sear artists use to keep steaks and pork chops curl-free.
To prevent curling, cut slits in the fat around the raw pork chop at half-inch intervals with a sharp knife. Food & Wine recommends making the incisions at half-inch intervals, cutting into the fat right to the edge of the meat, but Cook's Country suggests home cooks place one every two inches.