Beans on toast is a British staple.
Not a British roll here.
People here give the strangest looks when mentioning beans a toast.
Add a little garlic and chilli to the beans and fry the bread instead of toasting it.
Whenever I have some cooked leftover potatoes, I like to spread some butter or mayonaise on bread, then put the sliced potatoes on the bread and sprinkle with salt. Depending on the species of potato, it can be a bit bad though.
I toast my hamburger buns in mayo, though, I will admit. It works alright as a butter substitute. I always put mayo in my sandwiches anyway, so I might as well put it on when I toast the buns. It works well.