Boil potatoes, peel off and mash completely
let it cool

Cutt onions into rings, add half amount of spices and lemon juice, and mix with fork

Now add remaining spices in boiled potatoes and mix well

Apply ketchup and mayonnaise on bread slices

Now spread some onions rings on 1 slice and potato mixture on other slice

Put 1 slice on it and cut diagonally

Serve with ketchup