very similar in outcome to midwesterner's tip:
first, clean those livers well, cut out of connecting tissues with sissors and wash out any blood clots, keeping lobes as whole as possible (some infractions are tolerable). chop onions and garlic cloves.
brown chopped onions and garlic cloves in oil (olive oil is good but not absolutely necesary. any oil or fat like chicken or goose fat) will do, but don't use much. midway through saute (when onions START to become translucent), add sliced champingion mushrooms and livers (all this blotting and drying business is superfluous). continue to saute gently while mixing until the onion is limp and the livers are VERY pink in the middle, which is indeed 4-6 minutes later. Don't leave the stove unattended at this stage; chicken livers suffer terribly by overcooking, and that's what you should pay attention to.
add salt and pepper to taste (taste the liquid in the pan). Then, turn the heat way up, and when it is sizzling, splash in any dry RED wine, nasty or not. once the pan is very hot again turn to simmer, mixing occassionally (try to avoid breaking up the livers) for maybe two minutes. avoid overcooking!
if you need to keep this warm, before serving, turn the heat off as soon as the pan has reheated after adding wine.
very nice with rice