Pat the pork tenderloin dry
Trim any silver skin
Rub with olive oil or melted butter
Season generously with salt
Add black pepper
Use garlic powder
Use onion powder
Add paprika
Add dried thyme or rosemary
Add a pinch of cumin if desired
Add brown sugar for a sweet crust
Add chili powder for heat
Add mustard powder for tang
Add a little cayenne if desired
Massage the seasoning evenly over all sides
Let it rest for 15 to 30 minutes before cooking
Refrigerate longer if marinating overnight
Bring to room temperature before cooking