Heat the milk in a saucepan until it is steaming. Do not boil! Remove the pan from the heat. Using an electric mixer, or whisk, beat the 6 egg yolks with the sugar and salt until it becomes light and creamy. Add the warm milk and mix. Transfer the mixture to a double broiler and cook over simmering water until the custard is thick enough to coat a wooden spoon. I make this every year at Christmas! It is great served with fruitcake or pound cake