Dissolve the yeast in the warm water. Heat the milk to lukewarm and add the butter. Stir the milk and butter mixture into the yeast. Add the salt, sugar, egg and egg yolks, mixing well. Gradually stir in enough flour to make a soft dough.
Turn the dough out onto a floured board and knead it lightly until smooth and elastic. Place in a greased bowl, turning dough to grease the top, and c