What recipe method is used in turducken, stuffing one animal inside another?

The recipe method used to stuff one animal inside another is called engastration.

Engastration is a cooking technique in which the remains or carcass of one animal are placed inside another, usually after the animals have been deboned. Turducken is a familiar modern example: chicken is placed inside duck, and duck is placed inside turkey, with seasoning or stuffing often added between the layers.

The word is related to the Greek term for the stomach or belly, reflecting the idea of one animal being enclosed within another’s body. The technique is much broader than turducken and has appeared in elaborate multi-animal dishes across different periods and cuisines.

Engastration is often confused with ordinary stuffing, but the distinction is scale: stuffing fills a cavity with ingredients such as bread, herbs or sausage, while engastration places another animal or animal carcass inside. Spatchcocking means flattening poultry, barding means covering meat with fat, and trussing means tying food into shape; none describes a bird-within-a-bird construction.