This is a classic recipe for fish with tartar sauce.
Preheat oven to 450 degrees F.
Place breadcrumbs and melted butter in separate shallow dishes.
Cut each fish fillet in half.
Season fish with salt and pepper.
Dip fish into butter, then into breadcrumbs, coating completely.
place fish on baking sheet.
Bake fish until crisp, brown and just cooked through, about 12 minutes.
Meanwhile, stir mayonnaise, relish, dill in small bowl to blend.
Season tartar sauce with salt and pepper to taste.
Transfer fish to plates and serve with tartar sauce.