It is really two restaurants under one name

Heun Phen is in the day a local northern Thai food Canteen with little decor. It is a local haunt in the day time. A must try foodie treat in Chiang Mai not to be missed

At night they open the more elegant side for dinning. It is popular in the evening with  Bangkok customers seeking authentic Lanna cuisine.

Sadly: I personally find the two restaurants food quality varies too much to recommend that you choose to eat in the evening but do not miss it in the day time.