In small bowl or a cup mix all dry ingredients such as onion powder, garlic powder, ground black pepper, dried oregano, coriander and salt. Rub the seasoning mix all over the tenderloins, ensuring that no spots are left unseasoned. Place tenderloins in a zip-lock back, close and refrigerate for 8-10 hours. If you are in a rush, you may skip the refrigeration, but tenderloins will be much more flavorful if you let them marinate in seasoning. Try not to skip this step.