These Wikipedia articles have a lot of good material for those who aren't aware: https://en.wikipedia.org/wiki/Jewish_peoplehood and https://en.wikipedia.org/wiki/Who_is_a_Jew%3F
I'm Tunisian and I consider myself Arab, but many other Tunisians consider themselves (ethnically) Maghrebi and/or Amazigh. Tunisia and the remaining Maghrebi countries are part of the Arab League, though.
I'm sure it's even more complicated for Tunisian Jews :P
For Lybian Jews, it's not complicated at all.
That said, the 2014 Tunisian constitution and its protections for freedom of religion was a huge step forward, and gives me a good bit of hope for the future.
I recently had the opportunity to try one a few months ago. So good.
If you are looking for a standard Tunisian sandwich, I asked my wife and she said this one looks good: https://www.saveur.com/article/Recipes/Tunisian-Tuna-Sandwic....
Fricassee is another tasty Tunisian tuna-based sandwich, but it requires that you also prepare the bread: http://www.afooda.com/tunisian-fricassee-fricasse-roll/