chicken liver
The liver of the chicken, small, tender and mild compared with beef or pork liver.
Caution: Chicken liver can carry Campylobacter and should therefore be cooked until it is no longer raw inside.
Chicken liver is sold fresh or frozen in many supermarkets, though not all; butchers, poultry shops and Turkish or Middle Eastern grocers carry it reliably. It is tender and creamy with a mild, iron-like taste, and turns dry and grainy when overcooked.
Substitute:
Duck liver comes closest but is richer and stronger; calf's liver is firmer and needs to be cut small, while beef or pork liver taste noticeably stronger and are a poor match.