The staple foods of Bhutan are red rice (like brown rice in texture, but with a nutty taste, the only variety of rice that grows at high altitudes), buckwheat, and increasingly maize.
The diet in the hills also includes chicken, yak meat, dried beef, pork, pork fat and mutton. Soups and stews of meat, rice, ferns, lentils, and dried vegetables spiced with chilies and cheese are a favorite meal during the cold seasons. Zow shungo is a rice dish mixed with leftover vegetables. Ema datshi, made very spicy with cheese and chilies, akin to chili con queso, might be called the national dish for its ubiquity and the pride that Bhutanese have for it.
Other foods include jasha maru, a chicken dish; phaksha paa and fried rice. Dairy foods, particularly butter and cheese from yaks and cows, are also popular, and indeed almost all milk is turned to butter and cheese. Popular beverages include butter tea, tea, locally brewed rice wine and beer. Spices include cardamom, ginger, chilies, garlic, turmeric and caraway. http://en.wikipedia.org/wiki/Bhutanese_cuisine
Cooking food the Bhutan way is quite characteristic and clever. Ingredients in a pot are placed over the heat and cooked with minimum amounts of water. The dish is stirred frequently while cooking and the water level watched being added to with splashes as it begins to dry. This produces a food of correct texture and minimises on the use of cooking fuel.