Cheese and pickle. Also, Brie and Cranberry.
Chicken in almost any form. As a kid, when we had a roast chicken, it was made to last over several meals, and one real treat was chicken sandwiches for Sunday tea.
Crisps. A favourite late supper just before bed when I was little, watching Starsky and Hutch. I found out the hard way when I was a kid that these have to be eaten fresh. I asked for them for my school lunch once, and found that the marg made the crisps go soggy. A sandwich of slightly salty damp discs of potato is not the same.