Gristly means rubbery or full of cartilage. The hardest part of your trip to rural China might be graciously accepting and attempting to chew the gristly meat your hosts offer you.
The Old English word that spawned gristly is gristle, literally meaning "cartilage." When meat in particular is hard to chew, it's gristly. This adjective looks and sounds like grisly, which describes something that is disgusting or horrifying. To some people — picky eaters among them, attempting to eat gristly meat can be a truly grisly experience.