En vessie

En vessie is an unusual French cooking technique that's usually done with a pig bladder which is used to enclose the meat and keep it succulent and juicy. One of the most popular applications of this technique can be seen in a dish callet poulet en vessie, in which Bresse chicken is first stuffed with foie gras, white wine, and black truffles, steamed, then enveloped in a bladder.

The chicken is then poached in chicken broth, thus allowing the steam to come into the bladder and making the meat very flavorful and aromatic while remaining extremely moist.