Dissolve yeast in 1/2 cup warm milk till foamy. Sift flour, sugar, salt into a large bowl.Make a well in the flour mixture and add the yeast mixturee, with oil or melted butter and the remaining milk.Knead dough until springy adding more flour if necessary. Cover and let rise in a warm place until double.Punch down and mix in walnuts and onions.Shape into 4 rounds and place in a greased casserole dishes. Let rise double. Bake 400 for 45 minutes or until done and golden. Remove to racks to cool.