Preheat your grill to medium heat 450 degrees.
Once the grill is preheated, place your tenderloin in and pat it down, giving it good contact with the grill grates. We set our timer for 20 minutes total and flipped it at the 10-minute mark.
Once the timer is completed, we use an internal temperature thermometer to ensure it has reached the required internal temperature that is suggested by the FDA.
Then remove your tenderloin from the ninja foodi grill, set it on a plate, and cover it with tin foil. Allow it to rest for another 10 minutes total.