We know wolffish only from books, but one of the best, James Peterson’s Fish & Shellfish, says you’ve got a wonderful treat in store.
You've already done the hard part - getting the toothy beast subdued and into the boat without losing a finger of two. The reward is a lean, relatively firm, and delicately flavored fish. Wolffish is always cooked filleted or in steaks, never whole, and responds best to poaching, braising, panfrying, steaming, or deep frying.
Peterson recommends against grilling it, as it tends to stick.