cut gizzard and salt it for a couple of hours and soak it into oil. Olive oil is much richer, I recommend not to use ex-virgin, pure olive oil is enough. Heat the oil in low temp, 60 degree Celsius for a hour. 砂肝をオイルでコトコト煮込んで、砂肝のコンフィ。人参とか玉ねぎ入れとくとダシが美味い!