For those of you who don't know, this is what it is :)
Welsh rarebit or Welsh rabbit is a dish made with a savoury sauce of melted cheese and various other ingredients and served hot, after being poured over slices (or other pieces) of toasted bread, or the hot cheese sauce may be served in a bowl accompanied by sliced, toasted bread. Welsh rarebit may be eaten with the use of a knife or fork or both. The names of the dish originate from 18th century Great Britain. Welsh rarebit is typically made with Cheddar cheese, in contrast to the Continental European fondue which classically depends on Swiss cheeses.
"Eighteenth-century English cookbooks reveal that it was then considered to be a luscious supper or tavern dish, based on the fine cheddar-type cheeses and the wheat breads […] .