Meaning
紅芋 (べにいも, Beni-imo) is Purple sweet potato, a Japanese food (plants, tubers).
What is Purple sweet potato?
Beni-imo refers to a purple yam species ( Dioscorea alata ) from Okinawa. Another name is daijo (ダイジョ, 大薯). It's used for a lot of dishes, including tempura , fries, pastries, donuts, and ice cream, which receive an intense purple color from it. The picture shows a pastry with sliced white and purple yam on top.