This bierok is good and makes a lot. For dough, put package of yeast in bowl with a little warm water. Then melt a stick of butter in pan and add 1 1/2 c milk and heat to lukewarm. Add to bowl that has 5 c flour, 1/2 c sugar, 1t salt. Add yeast and 2 eggs and mix together and let rise til double. In pan, fry one chopped onion in olive oil, then add 1lb ground beef and cook. Add 1/2 cabbage chopped and cook. When cooked add 2T dijan mustard, 1c grated cheddar, and salt and pepper. Split dough in 12 balls, roll ball into circle, put 1/4c filling in each and fold over and pinch. Bake at 350 for 1/2 hour then brush tops with melted butter.