Pat pork dry and season with salt and pepper. Stir together cornmeal and cumin and transfer to a plate. Turn pork in cornmeal mixture to coat well and discard any remaining mixture.
Heat oil in a 10-inch nonstick skillet until hot but not smoking and brown pork, turning, about 3 minutes.
Transfer pork to a shallow baking pan and roast in middle of oven until a thermometer inserted diagonally at least 2 inches into pork registers 155°F, 30 to 45 minutes.