Pour boiling water and vinegar over the pre-cleaned whole livers and let them sit for 10-odd minutes. Then drain them well. Beat the egg whites with a pinch of salt, add the oil, beer and flour and gradually form a thick paste.
Dip each liver in the crumbing, it has to absorb it well. Optionally, add chili, cayenne pepper or paprika for a spicier taste. Heat oil in a frying pan and optionally add a little vinegar, so the crumbing does not absorb much oil.
Dip the livers in the crumbing and drop them in the hot oil. Put a cover or newspaper on, to prevent spraying. Fry for 2 minutes and then turn them over.