Welsh rarebit is a dish made with a savory 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 maybe
served in a chafing dish like a fondue, accompanied by sliced, toasted bread.
The names of the dish originate from 18th-century Britain. Despite the name,
the dish does not actually contain any rabbit.
Welsh Rarebit - delicious. magazine
The first recorded reference to the dish was "Welsh
rabbit" in 1725, but the origin of the term is unknown.
There is some suggestion that Welsh Rabbit derives from a
South Wales Valleys staple, in which a generous lump of cheese is placed into a
mixture of beaten eggs and milk, seasoned with salt and pepper and baked in
the oven until the egg mixture has firmed and the cheese has melted. Onion may
be added and the mixture would be eaten with bread and butter and occasionally
with the vinegar from pickled beetroot
Resource
Welsh rarebit, Wikipedia