For these, pound two or three hard-boiled eggs, a small piece of butter and two teaspoonfuls of grated cheese, and of tomato puree, until a smooth paste is formed. Melt a lump of butter in a saucepan, add the mixture and stir until it is quite hot. Then spread between fingers of hot buttered toast. Garnish the top of each sandwich with the whites of the eggs and serve very hot.