Scald milk and cool to warm. Mix cornmeal in boiling water and let sit 10 minutes. Add yeast to warm water and let sit foamy. Add milk and salt and mix well. Add butter, sugar, yolks and mix well. Gradually add to warm cornmeal mixture. Stir in enough flour to make a soft dough. Knead smooth and elastic on floured surface. Let rise double in a greased bowl. Punch down and let rise double again. Shape into 2 1/2 inch balls( or larger, one ball to a muffin tin ) and place in greased muffin tins. Let rise double. Bake 400 about 18 minutes or until golden. All rising are necessary to produce the lightest texture. Amount depends on how large your dough balls are, size of tins etc.Best eaten warm. Reheats well.