Marie Rose Sauce is a thick, pink uncooked dipping or condiment sauce used with fish and seafood.
Generally, its base ingredients are one part ketchup mixed with six parts mayonnaise (e.g. 1 tbsp ketchup, 6 tbsp mayonnaise.)
Sometimes a tablespoon of lemon juice and a dash of something zippy, such as a chili sauce (such as Tabasco), or cayenne pepper is added, though that starts to approach Seafood Sauce territory.
Marie Rose Sauce is usually served with shrimp or battered fish; sometimes served with French Fries in Belgium.
Not the same as Thousand Island Dressing or Russian Dressing. Similar to, but not the same as, Fry Sauce.
Use a light hand with the ketchup, as the sauce should not taste of ketchup.
Marie Rose Sauce was very popular in the UK in the 1970s, being served with Prawn Cocktail (aka Shrimp Cocktail.)