Welsh rarebit

Method

Melt the butter in a saucepan over medium heat and whisk in the flour to create a roux, cooking gently for 1 minute. Gradually add the milk, stirring constantly to avoid lumps, and cook until the sauce thickens, about 3-4 minutes. Remove from the heat and stir in the grated cheddar cheese, mustard powder, and Worcestershire sauce until the cheese is fully melted and combined. Add the ale and mix well, then cool slightly before whisking in the egg yolk, ensuring the mixture doesn't curdle. Season with salt and cayenne pepper to taste. Spread the cheese mixture generously onto each slice of toasted bread and place under a hot grill for 2-3 minutes until golden and bubbling, taking care not to burn the top.