Baked Haddock au Gratin January 13, 2021 667 × 1000 Baked Haddock au Gratin Recipe Baked Haddock au Gratin This Baked Haddock au Gratin dresses up mild white fish fillets with a delectable cream sauce topped with breadcrumbs and cheddar cheese. Serve with rice or choice of potato and side vegetable(s).