Sear the tenderloin on the hottest part of the grill for about 1 ½ minutes on each side and then cooking over either direct heat, 2 to 3 minutes more per side, or indirect heat, for 10 to 15 minutes more without turning. 5. Pan-roast it: This is my favorite method of cooking pork tenderloin. Take the tenderloin out of the fridge 30 minutes before cooking. Preheat the oven to 425 degrees. Film an ovenproof skillet with oil and sear the tenderloin over medium-high heat to brown all sides, about 5 minutes in all. If you’re using a glaze, apply it now. Place skillet in the oven and roast 15 to 20 minutes, until internal temperature is 145F degrees.