Poke the pork tenderloin all over with a fork. This will allow the marinade to really absorb into the pork.
In a small bowl whisk together 1 1/2 tbsps chipotle in adobo sauce, 3 tbsps maple syrup, 1 tbsp lemon juice, 1 tbsp chopped cilantro and 3 cloves minced garlic.
Place pork in a large storage bag and pour marinade over the pork. Seal bag tightly and place in the fridge to marinade for 4 hours up to overnight.
**Remove pork from the fridge about 30 minutes before cooking.
Preheat oven to 400 degrees.
Heat 1 tbsp of oil in a cast iron skillet (or other oven safe skillet) over high heat. Once the skillet is very hot, carefully sear pork tenderloin (WITHOUT DRIPPINGS + discard leftover marinade) for about 2-3 minutes on all sides until you have a nice crust.
Transfer to the oven and cook for about 12-14 minutes. When done, pork should be at least 145 degrees but I prefer mine cooked to 150 - 155 degrees. Check temperature with a meat thermometer.
When done, remove pork from the oven and transfer to a plate. Cover with foil to let rest for a few minutes.
Slice and serve pork with drippings and a fresh sprinkle of chopped cilantro. Enjoy!