Don’t know if its Cuban or not (didn’t get to eat black beans when I was taken there involuntarily years ago) but I just soak the beans, and cook in enough water to cover + an inch with a smoked ham hock, a couple of garlic cloves, bay leaf, thyme & a whole onion with a couple of cloves in it. Usually add some ground cumin & red pepper at the end. Key thing is to not add salt or acid (e.g., tomatoes) until done or almost so. If you do, the skins get tough and no amount of cooking will soften them up (the salt in the ham hock doesn’t seem to hurt). Also, this is much better if allowed to sit overnight — the liqid gets nicely thickened.
Over rice, with chopped scallions on top.
NB: Smoked sausage (andouille, kielbasa, etc.) is also good in this, as is a shot of rum or sherry. I