Grate the cheese finely.
Put it into a pan with the butter and ale and stir vigorously until creamy.
Then add the Worcester sauce, lemon juice or vinegar and the eggs, previously beaten.
Season to taste with celery salt and cayenne pepper, and continue stirring briskly until the mixture thickens.
Trim the toast, and cover with cheese mixture.
Garnish with parsley.
Serve as hot as possible.