Wash fish with cold water and pat dry.
Rub the fish with olive oil.
Place on a plate and give a good sprinkling of both spices, about equal of both on the meat portion of the fish.
Coat with sliced onion rings, and place on the grill.
Shut the lid and cook until done (time depends on size and thickness of filet).
Fish will be a lighter pink and flaky than when you started. Great taste! Easy.