Toast the bread slices. In a large saucepan stir together the cheese, butter, and half the beer. Cook over a low heat, stirring, until the cheese and butter melt and become thick. Do not boil. Remove the pan from the heat and whisk in the egg yolks, one at a time, mixing well. Add the Cayenne and the remaining beer. Return to the heat and continue cooking over a low heat, stirring constantly, until mixture becomes very creamy. To serve, place the toast in shallow ovenproof soup bowls and ladle over the cheese mixture. Place in a preheated 350F oven for 8-10 minutes, until golden. This dish can be prepared in advance and placed in the oven just before serving.
