Combine 1 lb 8 oz/680 g of the milk, 3½ oz/100 g of the sugar, and the salt in a nonreactive saucepan and bring to a boil, stirring gently with a wooden spoon.
Meanwhile, combine the cornstarch with the remaining 3 oz/90 g sugar. Stirring with a whisk, add the remaining 8 oz/230 g milk. Add the egg yolks, stirring with the whisk until the mixture is completely