Scald the milk in the top of a double boiler. Separate two of the eggs, set the whites aside, and beat together slightly the one egg, two yolks, four Tablespoons sugar, and salt.
Add the scalded milk to the egg mixture, mix thouroughly, and return to top of double boiler. Cook over hot water, stirring frequently, until the mixture coats the spoon.
Remove from heat, add vanilla, cool, and pour into a glass dish or into custard cups. Note: I pour this through a strainer to catch any fragments of cooked egg white, which can be an unpleasant surprise while enjoying the custard.
Beat the two egg whites untill stiff, and beat two to four tablespoons of fine granulated or powdered sugar. (Another Note: I didn't have either on hand, so, not to be outdone, I put my sugar into a plastic bag and introduced it to my marble rolling pin.)
Drop the meringue onto the custard by spoonfuls, and chill thoroughly.