In 2-quart microproof casserole, melt butter on HI (max. power) 1 minute.
Add cheese, Worcestershire, salt, paprika, dry mustard, and cayenne; mix thoroughly.
Cook, covered, on 50 (simmer) 6 minutes, stirring once during cooking time.
Stir small amount of hot cheese mixture into the beaten eggs, then slowly add to hot mixture; stir briskly.
Gradually stir in beer, blend well.
Cook, covered, on 50 (simmer) 3 minutes.
Cook, covered, on 50 (simmer) 3 minutes longer.
Remove from oven.
Beat briskly with whisk to blend thoroughly.
Serve over toasted and buttered French bread.