The ingredients consist of shellfish, meat, potatoes, potato bread, chapaleles, and vegetables (sometimes including also specific types of fish). The quantities are not fixed; the idea is that there should be a little of everything. Each layer of ingredients is covered with nalca (Chilean rhubarb) leaves, or in their absence, with fig leaves or white cabbage leaves. All this is covered with champas and wet sacks, creating the effect of a giant pressure cooker in which the food cooks for approximately one hour.
Curanto can also be prepared in a large stew pot that is heated over a bonfire or grill or in a pressure cooker. This stewed curanto is called pulmay in the central region of Chile.
It is believed that this form of preparing foods was native to the "chono" countryside and that, with the arrival of the southern peoples and the Spanish conquistadors, new ingredients were added until it came to be the curanto that is known today. However, there are some who claim that the curanto is more evidence to suggest the theory that asserts that there was contact between America and Polynesia in the pre-Columbian epoch, given that almost all Polynesian cultures have similar cooking methods known variously as "imu", "umu", "lovo", or "hangi".