In a medium-size bowl whisk together the oil, cumin, chili powder, red pepper flakes and salt until combined.
Pour the marinade in a plastic zip bag and add the pork tenderloins. Close the bag and move everything around to ensure the pork is coated.
Refrigerate for at least 30 minutes or overnight.
Place the pork on a pre-heated grill (450° to 550°) and cook for 5-6 minutes per side or until dark grill marks are achieved and the desired internal temperature is achieved. I suggest removing it, once it hits 133° to 135° internally.
Remove the pork from the grill and rest on a plate or cutting board for 3-5 minutes before slicing and serving alongside the pineapple salsa.
Notes
Make-Ahead: While this is meant to be eaten as soon as it comes off the grill and is sliced, you can make this an hour ahead of time while keeping warm in an oven at 165°. You can only do this if you prefer the pork tenderloin to be well done internally.How to Store: Place covered in the refrigerator for up to 4 days. This will freeze covered for up to 2 months. Thaw in the refrigerator for 1 day before reheating.How to Reheat: Please note that reheating pork will cause it to immediately overcook. The best way to heat it up is in a pan in the oven at 350° until warmed.This pork is fantastic eaten by itself and would also go fantastic with chimichurri sauce in addition to the pineapple salsa.It’s important to rest this pork, or any protein, after cooking to allow for the juices to soak back into it making it more flavorful.The longer you can marinate the pork the better.For more flavor, try toasting whole cumin seeds over low heat while constantly stirring for 5 to 6 minutes or until toasted and extremely fragrant.When cooking at high temperatures on a grill here’s how long it will take to cook with the grill door closed: For Medium Rare: 3-4 minutes per side, medium: 4-5 minutes per side, for medium well: 5-6 minutes per side, and for well done: 7-8 minutes per side.