I like to do Onion crusted fish often. Take thinly sliced onions, dredge them in flour and fry them until crisp (aka haystack onions). Let them drain then grind them in a food processor with breadcrumbs, salt & pepper. Then crust one side of the fish using the standard flour, eggwash, breadcrumb (the breadcrumbs being your onion mix). Saute on uncrusted side and finish in the oven.