Chez Slah was fantastic but on the expensive side for Tunis. Watch your final bill, the prices were inflated but I didn't want to spoil the atmosphere of many locals that were eating there.

My hotel recommended Café Bar Restaurant L'orient and the fish dinner was very good and the prices were reasonable.

The only pizza I had was in Sidi-Bou-Said, at Pizza Positano, a delicious wood fired pizza and even my hands were black after consuming it!

My best Tunisian meal was in the Sousse Medina, at Restaurant Café Seles. The fish was grilled to perfection with a wonderful salad and the roof top view was amazing! I was there in April 2017 and as you said, I also struggled to find a decent meal.