To make the pudding, stir together the sugar, cornstarch, and salt in the top pan of a double boiler. Mix in the egg yolks and place the pan over its simmering water base. Pour in the warm milk gradually, stirring constantly. Continue to stir frequently as the pudding cooks. It will gradually thicken, usually in about 15 to 20 minutes, but don’t rush it. The pudding is d