Melt the butter in a saucepan and stir in the crabmeat (make sure that you have picked over the crabmeat removing all the shell), heat gently stirring together. Beat the egg yolks, cream, and sherry together and add to the crab, continue cooking and stirring until the mixture thickens, keep the heat on low, add the parmesan cheese and let it melt. Remove from the heat, season to taste with Tabasco sauce and lemon juice and let cool. Give the mixture a good stir, then pour into a dish, cover, and chill overnight.