Heat oil in a pan.Add the chopped onion and saute till translucent.Now add the rest of the ingredients and cook for sometime.Keep aside.

For dough, put the yeast,sugar,lukewarmwater in a cup and allow the yeast to activate.Put flour,salt,butter,yeast mixture,in a big bowl and knead to a smooth dough by adding lukewarm water.Cover the dough and rest it for 1hour. Divide the dough into 5 equal sized balls flatten the balls slightly with hands and put the prepared filling in the center and seal the edges giving the shape of buns. Brush the stuffed buns with milk and bake in a preheated oven at 180'c oven for 25-30mins.