Several countries in the world employ the ancient method of cooking meals directly in the dirt, from Hawaiian luau pits to the Finnish earth oven roast called rosvopaisti. The latter method starts with a pit being dug in the morning, which is then lined with rocks or bricks. After a fire gets rolling, marinated meat and vegetables are sealed in foil and dropped into the hole. Coals from the fire are shoveled on top, to provide a slow, wrap-around style of cooking that will take until about dinner time to be ready.
The type of meat used for rosvopaisti varies widely, largely depending on the available resources and number of people to be served. It would not be unusual for a whole lamb or calf to be used. Roast-sized portions of beef, pork, mutton or even bear is the typical choice, though — alone or as a combination. While the meat is marinating in oil and spices like thyme, rosemary, garlic, salt and pepper, the hole dug. It measures from 1.5 to 3 feet (about 0.457 to 0.914 m) deep and wide enough to accommodate the protein and any vegetables that will also be thrown in the pit.
A fire is built with wood on top of the pit by dropping the coals down into the hole. After the fire has largely subsided, about half of the coals are dug from the fire and set aside. Hot stones are placed in the bottom of the hole.
The rosvopaisti packages are placed on the stone in the pit, and then the extra pile of hot coals is shoveled back to its original place. To guard against rips and seal in the juices, some chefs also use baking paper and then foil the dampened newspaper with binding wire to wrap their roasts tightly. After the coals are returned to the pit, a fire should be kept burning to radiate a constant high heat through the food.
For large roasts and small animals in rosvopaisti, it reportedly will take from 8 a.m. to 5 p.m., to create the pit and heat the meat through — with at least five hours to cook the meat alone. Potatoes and other large vegetables will take less time though, and should be dug into the pit a few hours before the meal. A meat thermometer can be used to determine when the meat is cooked through. For beef and lamb roasts, it will take a center at 130°F (about 54°C) to be medium rare.