Welsh cuisine butter was the primary cooking medium and basis for sauces. Salt was an important ingredient in Welsh butter, but also in early Welsh cheeses, which would sit in brine during the cheesemaking process. The Welsh were also early adopters of roasting cheese. An early incarnation of Welsh rarebit was being made in medieval times, and by the middle of the 15th century rarebit was considered a national dish. The acid soil of Wales meant that the milk produced by their cattle created a soft cheese, which was not as good for roasting, so Welsh people would trade for harder cheeses
Dream of the Rarebit Fiend McCay depicts marriage in "Rarebit Fiend" as "a minefield of hypocrisy, jealousy, and misunderstanding". McCay was a short man, barely five feet () tall. He was dominated by his wife, who stood as tall as he was. Images of small, shy men dominated by their taller or fatter wives appear frequently in "Rarebit Fiend". Gigantism, with characters overwhelmed by rapidly growing elements, was another recurring motif, perhaps as compensation on McCay's part for a sense of smallness. McCay's brother Arthur had been put in a mental asylum, which may have inspired the themes of insanity that are common in the