Pork/goose cracklings
The crisp, browned bits left behind when pork or goose fat is rendered, with a rich, nutty, roasted flavour.
Cracklings of this kind, made from rendered fat rather than skin, are sold by butchers, in Eastern European and German shops, and sometimes in jars. They are just as easy to make at home by dicing fatty pork back fat and cooking it slowly until the fat has run out and the pieces are golden brown.
Substitute:
Rendering your own pork back fat gives exactly the same result. Crisp-fried bacon works at a pinch but adds a smoky note, and bagged puffed pork rinds are not a substitute, because they are hollow, dry and differently seasoned.