Grate or cut into small pieces fresh American cheese. Place it in a saucepan or chafing-dish with three quarters of the ale. Stir until it is entirely melted; then season with the mustard, salt, and pepper, and pour it over the slices of hot toast, cut in triangles or circles. Everything must be very hot, and it must be served at once, as the cheese quickly hardens. Some use a scant teaspoonful of butter (more will not unite), a few drops of onion-juice, and the beaten yolks of two eggs, added just before serving. The egg makes it a little richer and prevents the cheese hardening so quickly. Milk may be used instead of ale to melt the cheese, in which case the egg should also be used. If any of the cheese fondu is left, it can be heated again with the rest of the ale for the second helping.