PUT in a press cooker beans, add water to fill ¾ of the pot, add a half of onion, garlic and salt; cover and let it cook for 40 minutes after cooker starts to whistle.
For the sauce:
Roast tomato, onion and garlic, turn them around for several times; once they get browned, blend it with cilantro and salt; just the necessary to get a thick sauce.
ADD an oil tablespoon in the pot, pour the sauce and let it boil, add beans and a little of its soup, be careful, it can´t be too liquid or too dry,finally, season it.
ADD onion, cilantro and radish finely chopped.