Thin sliced liver about 1/3 inch thick. Cut an onion into strips fry in olive oil at medium till soft and caramelized. drop the liver strips into the pan with the onions and fry both sides lightly till they change colour and brown a little. put in a couple of table spoons of ketchup and a couple of spoons of yellow hotdog mustard. stir for a minute or so over heat till the liver strips are coated and the mixture goes brownish and darkens.
We eat it with mash potato and sauteed cabbage.
believe me it tastes great and you would never know that the tangy sauce came from ketchup and mustard.
Do not over cook!