I have had chicken in a Yunan pot, but not Lion's Head soup. I haven't seen it at any of the local places around here.
Lucy Ho's Chinese Cookbook, which I bought from Dover Publications years ago has the recipe.But it's ground pork with seasonings, and cabbage and that's it.No noodles, etc.
Most recipes I have seen for it entail cabbage and ground pork, no porkbelly and that's it.No noodles,etc.
In my book there are a couple of recipes for a Chrysatemum Hot Pot and another hot pot.
Meat and vegetables are sliced rather thin and put on seperate plates.Can't recall if noodles are involved. A pot of chicken broth is placed on the table,and chacoal supplies the heat.The chinese have special pans for this,or you can use a chafing dish. The meat and vegetables a dunked into the hot broth till quickly cooked and eaten.At the end, a raw egg is broken into your bowl, and the savory broth poured on to, to poach the egg,or you could stir the egg around, like for egg drop soup.
But that doesn't sound like what you had.
Never had steamed pork belly, most restaurants around San Antonio don't serve it, unless maybe on the chinese language menu for chinese customers.
The use of bad pork belly sounds to me like they want to get their money's worth out of the meat.