Heat oil and add mustard
Add chilly,ginger and curry leaves
Add onions and wait till it turns golden.
Add turmeric, salt and mix it well
Mash potato and mix it well.
Take bread slice and dip it in water and place it on plate
Add some potato curry and roll it and bind it
Take oil on a heated pan and shallow fry on all sides.
You can deep fry it.
Serve with tomato ketchup