If you've ever pan fried steaks or chops, you know they can easily curl up a little once the heat rises. This is called "buckling," and it's easy to fix, thanks to this tip from America's Test Kitchen. Just make a few small slits around the sides. They'll stay flat and sear evenly.
Instead of pressing down on them with a spatula or tongs, this tip will ensure even cooking without damaging the meat you're trying to cook. Remember not to cut too deep: you don't want to slice right into the meat.
Thick cuts won't need this as much since they'll be heavy enough to lay flat, but meat that has that nice band of fat around the outside can buckle quickly. This is because the fat loses its moisture faster than the rest of the meat, and shrinks while cooking. It pulls itself tighter around the meat, causing the rest to pull up from the sides. The video does a great job of showing you why this happens, and giving you a before/after picture of how well it works.
Super Quick Video Tips: Prevent Pan-Seared Pork Chops from Buckling [America's Test Kitchen]