- Melt the butter in a saucepan and add in the flour to create a roux. Keep stirring for a few minutes to get a good consistency and to stop the roux from burning.
- Then slowly stir in the warm beer to create a thick yet smooth sauce.
- Add in the grated cheddar and keep stirring until it is melted. Now just add in the Worcestershire sauce and English mustard, and season with a little black pepper.
- In the meantime, light toast and butter the bread and then pile up the cheesy mixture on each slice.
- Finally, cook it under a hot grill for a few minutes until it starts to brown and bubble.