M&S Wild Icelandic Haddock Fillets Frozen Frozen Icelandic haddock fillets. Try topped with a creamy mornay sauce and oven bake until bubbling. Cooks in 10 minutes from frozen. Contains 4 to 5 servings. Our M&S seafood products have been sourced from fisheries and fish farms in a way that minimises their ethical and environment impact, while guaranteeing you the highest quality, delicious seafood you’d expect from M&S.