M&S 2 Battered Haddock Fillets Two haddock fillets in a light golden batter. Simply oven cook and serve alongside chunky chips and mushy peas. Serves 2. 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.