Dissolve the yeast in ⅓ of the warmed milk and the same of water. Make a stiff dough with some of the flour and the yeast, milk and a little water. Keep in a warm place and set to rise for ½ an hour. Work the remaining flour with the water and milk and add the dough that has risen. Work and knead thoroughly. Now let the dough stand for 1 hour, then fold over. Then divide the dough in 4 oz pieces and shape into compact balls. Let stand for another ½ hour. Shape them into round rolls, brush over with yolk of egg and set in a moderate oven till done.