Most people think Welsh Rarebit is some sort of heavy rabbit stew or something. It’s not: It’s cheese and beer on bread—no rabbit in sight—and when done right, is absolutely irresistible: creamy, funky, and sweet.
Despite its relatively straightforward preparation, people get it wrong more often than they get it right—even in England, its native land. It isn’t just a slice of melted cheese on bread (that’s blasphemy). To make it, cheese and beer—and a few other piquant ingredients—are whisked together to make a Mornay sauce, cooled, and then smeared on toast before being broiled.
In order to make a proper Welsh Rarebit, you must make a proper Mornay sauce: You must cook out the flour in the roux for enough time so as to lose the raw flour flavor. You must whisk constantly so that the flour cooks out and the roux thickens, but it must not color. You then add the stout and cream, followed by the cheese. When you add the cheese, lower the heat and ensure that it is all uniformly melted. Then cool fully before applying to the toasted pieces of bread. Grill the rarebit until nicely golden; cut into strip pieces and season liberally with the Worcestershire sauce. Enjoy!