Boil and mash potatoes, and mix in the butter, salt and cream. Crisp the bacon and finely crumble it. Cook the onion in the bacon fat till tender but not dark. Add to mashed potatoes along with parsley, cayenne, mustard, nutmeg and Worcestershire. Add enough top milk or light cream to give the consistency of cream soup. Sprinkle crumbled bacon and grated cheese over the top and brown lightly in the oven. Serve piping hot.
