In a large saucepan, melt butter over medium heat. Stir in flour until blended; gradually whisk in beer until smooth. Whisk in stock, Worcestershire sauce, mustard, salt, pepper and cayenne.
Bring to a boil, stirring constantly; cook and stir until thickened, 1-2 minutes. Reduce heat. Gradually stir in cheese until melted. If desired, serve soup in bread bowls and top with crumbled bacon and shredded cheese.
Notes:
When I don't use bread bowls, I usually serve it with soft pretzels or crusty bread. And it's also an even bigger treat with slices of cooked bratwurst or kielbasa stirred into it. —Paula Zsiray, Logan, Utah
