In Tripoli, it is surprisingly hard to find a traditional Libyan restaurant. Most serve western-style cuisine, with a few Moroccan and Lebanese restaurants thrown in. There are also a number of good Turkish restaurants, and some of the best coffee and gelato outside of Italy. There are some wonderful Libyan dishes you should taste in case you are fortunate enough to be invited to a Libyan dinner party or wedding (be prepared to be overfed!). A favourite cafe for the local expatriate community is the fish restaurant in the souq. For the equivalent of a few US dollars, you can enjoy a great seafood couscous. A local speciality is the stuffed calamari.
Also recommend Al-Saraya: Food OK, but its attraction is its position, right in Martyr's Square (Gaddafi name: Green Square). Another good seafood restaurant is Al-Morgan, next to the Algiers Mosque, near 1st of September Street. Don't miss Al-Sakhra restaurant, located on Gargaresh Road; excellent food, live entertainment, and a rustic atmosphere. The flashy looking big fast-food outlets are a relatively recent arrival in Tripoli. These are not quite the multinationals but a close copy of them! They are springing up in the Gargaresh Road area -- a big shopping area in the western suburbs of Tripoli.
Try one of the best local catch fish named "werata" try this fish in grill or baked with local herbs and spices, and it is a guarantee you will love it.
Tea is the most common drink in Libya. Green tea and "red" tea are served almost everywhere from small cups, usually sweetened. Mint is sometimes mixed in with the tea, especially after meals.
Coffee is traditionally served Turkish style: strong, from small cups, no cream. Most coffee shops in the larger cities have espresso machines that will make espresso, cappuccino, and such. Quality varies, so ask locals for the best one around.
Alcohol is officially banned in Libya, though in reality, alcohol is readily available through a local black market (anything from whiskey to beer to wine). It should be noted that penalties for unlawful purchase can be quite stiff. Travellers should always exercise appropriate common sense with respect to local laws, local sensitivities and traditions.