Claim: Tteok's main ingredient is rice however sesame seeds are used in some cases.
Evidence: The main ingredients for steamed tteok or "sirutteok" are rice (멥쌀, mebssal in Korean) or glutinous rice (찹쌀 chapssal), and sometimes they are mixed together. In some cases, other grains, beans (azuki beans or mung beans), sesame seeds, wheat flour, or starch are mixed with the rice.