Boil ½ kg potatoes and mash them. Add 1 tsp soya sauce and 1 tsp white vinegar in 250 gm chicken mince. Cook it till the water dries. Then chop it with bread slices. Mix in mince, potatoes, crushed black pepper and salt. First make cutlets and then make a hole in the center with help of thumb. Dip the donuts in egg and roll them in breadcrumbs and fry them. Spread ketchup on the top of the donut. Serve.