Gently pound the pork tenderloins with a meat pounder to flatten them out. (optional)
Marinate the pork for 3 to 24 hours using your favorite marinade (see the post for marinade ideas).
Remove from the marinade and bring to room temperature while you prep the grill for two-zone grilling.
Season the tenderloins generously on all sides with kosher salt and freshly ground pepper and a drizzle of oil.
Grill the pork tenderloin over direct medium-high heat for 3 to 4 minutes per side to brown slightly, then move to the cooler side of the grill and continue to cook covered until the internal temperature reaches 145° F, about 10 to 15 more minutes. Use a probe thermometer to verify.
Transfer the cooked pork to a cutting board and rest for 5 minutes before slicing and serving with your favorite sauce.
Notes
Marinating is totally optional but highly recommended. If you don't marinate the tenderloins, drizzle canola or olive oil over the entire surface before seasoning. This will help the seasoning stick and prevent sticking to the grill.