Step 1: Prep pork
Sprinkle the pork with salt and pepper, chili powder, cajun spice, or the seasoning of your choice.
Put it in the oven at 400F for approximately 45 minutes to an hour, and remove when it reaches an internal temperature of ~140-145F* on your instant-read meat thermometer.
*Note: the USDA recommends 160F, but this produces a painfully dry bit of pork (especially with today's leaner pork) and is overkill, according to Cook's Illustrated. The Pork Board recommends 150F, which also turns out dry. Trichinosis is killed at 137F, so we're into the safe zone. The internal temperature will rise 5-10 degrees as the meat rests to redistribute the juices, covered, after cooking.