The tandoor is an oven - often a dome-shaped clay oven - used to cook foods at a high heat. Says Wikipedia, "Tandoori Chicken is a chicken dish dating back to the time of the Mughal Empire in Central and Southern Asia; it is still popular throughout that area. It has gained popularity even among people whose religion forbids the consumption of meat (Hinduism/Sikhism) in India.
The chicken is marinated in a yogurt seasoned with garam masala - garlic, ginger, cumin, cayenne pepper, and other spices depending on the recipe. It is traditionally quite hot. Cayenne, red chili powder, or other spices give it its red color. Turmeric produces a yellow-orange color. In some modern versions red and yellow food coloring is used instead. It is traditionally cooked at high temperatures in an earthen oven (i.e. tandoor), but can also be prepared on a traditional grill."
You can't go wrong ordering Chicken Tandoori, Imho.