Used only in 糌粑 (tsampa), roasted highland-barley flour that is the staple food of Tibet. It is eaten kneaded together with 酥油茶 (butter tea) into small dough balls.
The grain radical 米 on the left files this as a milled-grain food. It is fitting: tsampa is ground barley flour, so the rice/grain radical signals 'a powdered cereal' even though the grain is barley, not rice.
The right side 昝 supplies the sound (zǎn → zān). 糌 is a transliteration character coined to write the Tibetan word, so the meaning comes entirely from the grain radical while this part only carries the pronunciation.
