To make a complete dish, I have added nagaimo (the sliminess disappears leaving a very nice texture), daikon (I precooked and then finished cooking in the broth), potatoes (I also precooked), and carrot; all worked well.
Today, I microwaved small red potatoes and placed them in the black vinegar sauce with carrot and simmered them for 20 minutes with chicken thighs. I also added steamed broccoli. I served all these with Japanese hot mustard. So, I have been using the simmering broth for at least several months. The flavor is getting better and better. This time I did not remove the bone from the thigh but we could eat this chicken using chop sticks. The meat was succulent, flavorful and fell right off the bone.
Since the black vinegar is very mild, this dish will go with wine, especially sturdy reds. We had a very reasonably priced (read "cheap") Tempranillo Bodegas Ondarre Reserva Rioja 2004. This is a sort of everyday wine but went well with this dish.