In a large, resealable plastic bag, combine the oil, lemon juice, rosemary, red pepper, garlic and pork. Press out any air in the bag, seal and refrigerate for 6 to 8 hours.

Let the pork stand at room temperature for 1 hour. Preheat the oven to 400 degrees and preheat a griddle or a very large skillet. Remove the pork from the marinade. Scrape off most of the garlic and rosemary and season the tenderloins with salt and pepper. Set them on the griddle and cook over high heat until browned all over, about 6 minutes. Transfer the tenderloins to a large rimmed baking sheet and roast in the oven for about 14 minutes, until an instant-read thermometer inserted in the thickest part registers 130 degrees . Cover the tenderloins loosely with foil and let rest for 10 minutes before slicing and serving.