In a large saucepan cook chopped celery and chopped onion in butter till tender but not brown. Stir in beef broth, beerwurst, beer, mustard, basil, thyme, garlic powder, oregano, and 1/2 cup WATER.
Simmer, covered, about 10 minutes or till heated through. Top individual servings with the hot Cheesy Bread slices.
CHEESY BREAD SLICES: Arrange 4 slices French bread on a baking sheet; sprinkle with 1 cup shredded mozzarella cheese. Broil 3 to 4 inches from heat about 3 minutes or till the cheese is melted and lightly browned.