Bun is a small, usually sweet, bread. Commonly they are hand-sized or smaller, domed in shape, with a flat bottom. You can fill it with anything you want
Mix sugar with yeast, water, flour, yoghut, oil, egg and salt
Make a dough with some warm milk
Let it rise for 2 hours or until doubled in size
Make the dough into small balls, roll them firmly and place them slightly apart in a tray.
Brush with butter
Bake in preheated oven for 20 minutes
Brush with butter before serving