Haddock Mornay

What is it?

Haddock fillets come baked in a creamy Mornay sauce, which usually means a white sauce built with cheese, milk, and a little seasoning. In frozen-meal terms, it sits in the fish-and-sauce lane rather than with crumbed or breaded options, so you’re getting plain haddock in a soft, spoonable sauce instead of a coated fillet. M&S uses the familiar Mornay format here, which is close to a cheese sauce but typically a bit lighter and more delicate, with the fish doing most of the work in the tray.