M&S King Prawn Tomato & Basil Pasta Salad Pasta and succulent king prawns in a tomato and basil mayonnaise dressing. Ready to eat. Serves 1. 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.