3
Whisk the sugar, salt and egg yolk into milk before stirring in the starter and sifting over half of the flour. Roughly combine the ingredients with a fork, before sifting over half of the remaining flour. Turn the dough out on to a lightly floured work surface and knead until the dough is elastic and no longer sticky. You may need to add the remaining flour, but you may not. It will depend on the absorbency of the flour. This kneading will take a while, so be patient