In Yucatecan households, Monday means frijol con puerco. Not as a rule anyone enforces, just as a habit so old that cooks buy the pork on Sunday without discussing it. The usual explanation is practical: a pot of beans and meat sits on low heat for hours and asks almost nothing of the person watching it, which suited a day given over to washing and the start of the week. Whether or not that is the whole story, the rhythm has held, and in plenty of kitchens and cocinas económicas around Tulum you can still tell the day of the week by what is on the stove.

The dish itself is simple to the point of bareness. Black beans and pork go into one pot with onion, garlic and epazote and cook until the beans give way and the meat pulls apart under a spoon. What comes out is not a stew and not a soup but something between the two: a loose, almost black broth with soft beans suspended in it and pieces of pork that have taken on the bean flavour. It is served over white rice, in a bowl, with the broth soaking down through the grains.

Everything bright in the dish arrives at the table, not in the pot. A charred tomato salsa with habanero and sour orange, chopped white onion, a heap of cilantro, thin coins of radish and a wedge of lime. These are not optional garnishes. The beans are deep and a little heavy on their own, and the salsa and the raw vegetables are what make each spoonful land. A plate of frijol con puerco without radish looks to a Yucatecan eye like an unfinished plate.

Two things get lost outside the region. The first is the consistency: this should be soupy, not thick, and cooks who reduce it to a refried paste have made something else. The second is the cut of pork. Lean loin dries out and contributes nothing to the broth. What you want is shoulder with the bone in, or ribs, or a mix, with enough fat and connective tissue to give the beans body over three hours. Espinazo, the pork backbone, is what many cooks here use precisely for that reason.

It reheats better than it cooks, so make the full pot. The beans keep drinking the broth overnight, which means you will be adding water on the second day, and the second day is the one people quietly prefer.