Cut kidney in half horizontally and remove the white membrane. Score the outside lengthwise and crosswise ⅛” deep. Cut each half into 8 pieces, soak in cold water (changing the water several times.).
Soak jellyfish in cold water for 3 hours, dice into pieces 1” wide by 2” long. Cut the longer side into 6 or 7 strings, ½” long (producing a comb effect).