A triple-decker sandwich made with toast and filled with bacon, lettuce, tomato and mayonnaise. When I first lived in the States in the late 60's one of my treats was to go to Woolworth's in Danbury to have a 'BLT on toast' for the grand sum of 75 cents. In New York I'd go to Bloomingdale's for my fix. Coming, as I did, from a village in the west of England, I thought this was thoroughly exotic.