Simmer those in water for a while, with onions, pepper, and some spices, it’a very nice stock. Makes for a nice change from chicken stock, I think.
My uncle used to own a tavern…and he had big 5 gallon jars of these horrid things behind the bar! They looked like lab specimens, floating in preservative solution…bleeechh! Every once in a while, a customer would ask for one…and he’d fish one out for the guy. Absolutely disgusting!