In Jambiani beach there are quite a few nice little restaurants. They cook local dishes, mainly fish and rice ^^
The stone culture restaurant, right next to the Mango beach bar. In the north of Jambiani beach.
Entrance of the restaurant
I ordered fish filet with nuts, plus vegetable curry. You can choose rice or fries, I chose rice because I love rice, here in Zanzibar, people also love eating rice, which makes me feel like home (China).
Meal costs around 5€ with drink included, not bad.