Put butter or oil into large frying pan on high heat and add finely chopped onion fry until soft not brown. About 1-2 mins. Add sliced button mushrooms, the pepper corns (or chilli), salt and cook 1 more min

Slice the livers into 1cm strips. Then add to pan and turn every 2 mins adding the water after 1 min. Turn off the heat but keep turning until livers cooked through. (About 2-3 mins) add the vinegar and light to quickly heat on high for 1 min so very reduced. Serve with some nice bread and enjoy.