Welsh Rarebit (3 Ways)

At its most basic:

1/2 tablespoon butter
1/2 cup beer or ale
1/2 pound cheddar, grated
salt to taste
1/8 teaspoon cayenne
1/8 teaspoon dried mustard
Worcestershire sauce to taste
salt to taste

In top of double boiler set over simmering water, melt butter and add beer
When beer is warm, add cheese and stir constantly until cheese is melted and mixture is smooth
Add seasonings, stirring well

Serve on toast or English muffins
from Vegetarian Table: America (Madison)

A little richer:

2 tablespoons unsalted butter
2 tablespoons all-purpose flour
1 teaspoon Dijon mustard
1 teaspoon Worcestershire sauce
1/2 teaspoon kosher salt
1/2 teaspoon freshly ground black pepper
1/2 cup porter beer
3/4 cup heavy cream
6 ounces (approximately 1 1/2 cups) shredded Cheddar
2 drops hot sauce
4 slices toasted rye bread

In a medium saucepan over low heat, melt the butter and whisk in the flour. Cook, whisking constantly for 2 to 3 minutes, being careful not to brown the flour.

Whisk in mustard, Worcestershire sauce, salt, and pepper until smooth. Add beer and whisk to combine. Pour in cream and whisk until well combined and smooth.

Gradually add cheese, stirring constantly, until cheese melts and sauce is smooth; this will take 4 to 5 minutes. Add hot sauce. Pour over toast and serve immediately.