Pachamanca (from Quechua pacha "earth", manka "pot") is a traditional Peruvian dish based on the baking, with the aid of hot stones (the earthen oven is known as a huatia), of lamb, mutton, pork, chicken or guinea pig, marinated in spices. Other Andean produce, such as potato, green lima beans or "habas", sweet potato, occasionally cassava or yuca, and humitas (sweet treat) as well as ears of corn, tamale and chili, is included in the baking.
The dish is essentially made in the central Peruvian Andes in three main regions: 1) The upper Huallaga valley, in Huánuco and Pasco vicinity, where it is made with pork and seasoned with chincho, a local herb; 2) in the Mantaro valley and neighboring area around cities like Huancayo, Tarma and Jauja; they use lamb and a different seasoning; and 3) in several places of Ayacucho department. In the Peruvian Amazonia, the southern and northern Andes, and the mostly desertic coast the dish is uncommon due to the lack of firewood or the type of stones needed without any content of sulphur. Meat is wrapped in banana leaves before being put in this kind of earthen stove.
This important part of Peruvian cuisine, which has existed since the time of the Inca Empire, has evolved over time, and its consumption is now widespread throughout modern Peru, where regional variations have appeared in the technical process of production, but not in the ingredients or their baking. It's important to note that the preparation is not only limited to Peru, but also that it exists with minimal variants in other Andean countries, for example Ecuador.
Preparation begins with the heating of stones over a fire, and the meat is then placed on top. The fire is covered with grass and earth, and the resulting oven is opened up after around an hour and a half. Usually, a large quantity of meat is cooked, perhaps a whole sheep, to serve several people.