Yemeni cuisine differs markedly from the rest of the Arabian Peninsula, and is a real highlight of any trip to the country - particularly if shared by locals (which is an invitation most visitors will receive more often than they might expect).
The signature dish is salta, a meat-based stew spiced with fenugreek and generally served at the end of the main course. The taste may take newcomers by surprise, but it is a taste well worth acquiring.
Yemeni honey is particularly famous throughout the region, and most desserts will feature a liberal serving of it. Of particular note is bint al-sahn, a sort of flat dough dish which is drenched in honey. Other sweet foods well worth the trying are Yemeni raisins.
While not a "food" per se, something else to put in one's mouth is the qat leaf. This is the Yemeni social drug and is chewed by almost all of the population from after lunch until roughly dinnertime. The plant is cultivated all over the country, and most Yemenis are more than happy to offer visitors a branch or two. Actually chewing qat is something of an art, but the general idea is to chew the small, soft leaves, the soft branches (but not hard ones) and to build up a large ball of the stuff in a cheek. The ability to chew ever-increasing balls of qat is something of a mark of pride among Yemenis, and the sight of men and boys walking down the street in the afternoon with bulging cheeks is one the visitor will soon get used to. The actual effects of qat are unclear, although it generally acts as a mild stimulant. It also has something of an appetite-suppressant function, which may explain why there are so few overweight Yemenis in spite of the nature of their cuisine. Insomnia is another side effect.
Yemen is officially a dry country; however, non-Muslims are entitled to bring up to two bottles of any alcoholic beverage into the country. These may be drunk only on private property, and venturing outside while under the influence is not a wise decision.
Many juices and soft drinks are readily available, but you should avoid more scruffy-looking juice shops as they might be using tap water as base. Many Yemenis will drink tea (shay) or coffee (qahwa or bun) with their meals. Yemeni coffee is considerably weaker than the strong Turkish coffee found elsewhere in peninsular Arabia.
Tap water should be avoided. This is comparatively easy to do, as bottled water - both chilled and at room temperature - is readily available everywhere.