According to Wikipedia, "Marie Rose sauce (known in some areas as cocktail sauce or seafood sauce) is a British condiment often made from a blend of tomatoes, mayonnaise, Worcestershire sauce, lemon juice and black pepper. A simpler version can be made by merely mixing tomato ketchup with mayonnaise. The sauce was popularised in the 1960s by ***** Cradock, a British celebrity chef".
But the version I was taught to make as a catering student (one of several incarnations) used mayonnaise (home made, of course), tomato puree, Worcester sauce, lemon juice, seasoning and brandy. There are also some versions that use part cream, part mayonnaise. And as
@MrsA2 says, a simpler version is a mixture of mayonnaise and tomato ketchup. I make it sometimes and use part double cream, part mayonnaise, part tomato puree, lemon juice, a touch of chilli and a little soya sauce.
No breakfast for a while yet - I have an appointment in Stornoway at 9.20 for a PCR test so will wait until I get back to eat. Then it will be some of the sausage casserole I made a couple of days ago. Possibly it will be just one meal today. That's how yesterday ended up, unintentionally.