However, purple sweet potatoes aren't readily available. So, you'd have to order Japanese purple sweet potatoes special, and they're about $15.39 per pound. With prices being reasonable even online, ...

While Japanese mountain yams have plenty of cooked uses (they ... to American consumers in 2015 through their $100 gold-ube donut. The charm of this purple-fleshed yam quickly captivated other ...

This recipe from Houston chef Anita Jaisinghani of Pondicheri uses Japanese purple yam combined with the Idaho potatoes.