I went here recently and loved it so much I had to tell you about it...
Ariana II is an Afghan restaurant, located on Kilburn High Road, and it brings to you the best Afghan cuisine in friendly and comfortable surroundings.
For those not familiar with the food from Afghanistan, here's a little primer - the main focus is on kebab, the famous skewered meat popular in many countries, Turkey for example. The national dish is Kabuli Palaw, a sumptuous dish made up of steamed rice with raisins, lamb, carrots and more, similar to a pilaf - and something you should really try here.
The food is delicious, with a full menu stuffed with treats for you to dig into - I can recommend the Aushak for a delicious taste sensation. Also, when you have finished indulging yourself, make room for some nuckel for dessert. Nuckel is basically sugared almonds - really delicious when served with tea (though equally good with coffee in my opinion).
The restaurant itself is very comfortable, with many traditional decorations on display showing the culture of the county, which helps you really appreciate the food more.
One of the best things, the food is very reasonably priced, the service friendly, and the BYO bottle policy on alcohol (note not on soft drinks or water) help make it an even more affordable option for those who want good food, but may have budget restrictions.
Before you go, you probably are wondering about the "II" part of the name - let me enlighten you. The original Ariana was born in Manhattan, New York - hence the London version is the second one.