Welsh Rarebit

Instructions

1. 1 Melt the butter in a small heavy-bottomed saucepan over low heat. Add the flour and stir continuously with a wooden spoon for one minute to cook out the raw flour taste, forming a smooth golden paste without any lumps.
2. 2 Gradually pour in the ale or milk, whisking constantly to incorporate it smoothly into the roux. Continue whisking over low heat until the mixture thickens slightly and becomes glossy, about two to three minutes of steady stirring.
3. 3 Add the mustard powder, Worcestershire sauce, and cayenne pepper to the sauce. Stir well to combine, then add the grated cheddar cheese in three batches, stirring until each addition is fully melted before adding the next.
4. 4 Continue stirring the cheese mixture over the lowest heat until it becomes a thick, smooth, and glossy sauce that pulls away from the sides of the pan. Remove from the heat immediately once the desired consistency is reached.
5. 5 Toast the bread slices on one side only under a hot grill or in a toaster. Place the slices toast-side down on a baking tray lined with foil, so the untoasted side faces upward ready to receive the cheese mixture.
6. 6 Spread a generous and even layer of the cheese mixture over the untoasted side of each bread slice, making sure to push it right to the edges to prevent the bread from burning at the corners during grilling.
7. 7 Place the tray under a preheated hot grill for three to four minutes, watching carefully, until the cheese topping is bubbling vigorously and has turned a rich golden brown with darker spots. Serve immediately with a grinding of black pepper.