These are the small saucers of ribs that come round on the yum cha trolley, and they are one of the easiest dim sum items to make at home because there is no wrapping and no frying. Everything goes into one bowl, sits for a while, then steams.
Fermented black beans do the heavy lifting. Rinse them first to knock the salt back, chop them roughly so you get pockets of flavour, and spread the ribs out in a single layer so they cook evenly.