Step 1Heat the oven to 325 degrees.
Step 2Blend the garlic with the butter; butter one side of the bread and cut it in strips to fit a 1-or 1 1/2-quart shallow casserole. Line the bottom and sides of the casserole with the bread, butter side down.
Step 3Beat the eggs lightly, then add the wine, stock, Worcestershire sauce, salt, mustard, paprika and cayenne pepper, beating gently.
Step 4Gradually beat in the cheese and onion tops. Pour the mixture over the bread. Bake until the custard is firm, about 1 hour.