With a pork tenderloin: Season the meat, sear all sides in a very hot pan, and then finish in the oven at 350°F (175°C) degrees until the internal temp. hits 145°F (63°C). Then let it sit for 10 minutes, and cut 'er up.If you need it done faster, a higher oven temp will accomplish this, but may compromise quality.espite the currently accepted answer, there is no single best method to cook pork tenderloin. The main issue is getting it to a final internal temperature of about 145 F to 155 F (63 C to 68 C) depending on your preferences.