Mix mustard, onion and garlic in a small bowl. Spear pork with a fork. Rub mustard mixture over pork loin.
Combine remaining ingredients. Sprinkle spices over pork. Rub in. Place in refrigerator overnight.
Let stand at least 1 hour before grilling to desired doneness. Or roast in a preheated 525° oven. Place roast in oven and turn temp. down to 325°. Check center of meat with thermometer.