Mandala Society is a family-owned restaurant with bohemian design details. The food they serve is created with the local ecology in mind: it is plastic and meat free, serves vegan dishes and is organic where possible. The restaurant is located in the middle of the souks. On the terrace you even have a couple of tables which have an overview over the busy souks.
You can find a second Mandala Society restaurant in Essaouira (this is the first one).