Corned beef / bully beef
Not the American thing we call salt beef (which is excellent and one of my non-guilty pleasures) but the stuff that comes in cans from Fray Bentos in South America. Cheap meat and many food miles, but yummy salty fatty.
I tend to have enthusiasms for a particular food, and will eat a lot of it for a few weeks until I tire of it and move on to something else. Recently i have been making sort of ersatz Reuben sandwiches, with bully beef, emmental, sauerkraut, and mustard, often toasted gently in a frying pan to melt the filling.
Heinz Sandwich Spread
Finely diced vegetables in salad cream. Sweet and sour and crunchy. A good alternative to a pickle like Branston, especially before they did a sandwich version.
Salad cream is another of those dubious cost-reduced foods, like mayo but with less egg and oil, more vinegar, and added water and sugar. A stronger sweeter and more vinegary flavour.