Welsh Rarebit - NYT

Ingredients

2	tablespoons butter
2	tablespoons flour
¼	cup Dijon mustard
½	teaspoon cayenne, or to taste
¾	cup strong dark beer, like Guinness
2	tablespoons Worcestershire sauce, or to taste
1	pound Cheddar, Double Gloucester or other English cheese (or other good semi-hard cheese, like Comté or Gruyère, or a mixture), grated
4 to 8	pieces lightly toasted bread

Directions

1. Put butter in saucepan over medium heat and, as it melts, stir in flour. Continue to cook, stirring occasionally, until golden brown and very fragrant, 3 to 5 minutes. Stir in mustard and cayenne, then whisk in beer and Worcestershire sauce.
2. When mixture is uniform, turn heat to low and stir in cheese, stirring until smooth. Remove from heat and pour into a broad container to set. (You can refrigerate for up to a day at this point.)
3. Spread mixture thickly on toast and put under broiler until bubbly and edges of toast are crisp. Serve immediately.

Source

Diner's Journal, New York Times, 12/31/2008. Adapted from Fergus Henderson.