When using dried beans, I like to soak them for improved digestibility. I do this overnight in cool water, or for 6 hours. Then cook according to package instructions. For quicker cooking times, a pressure cooked can be used. This requires no soaking and the beans cook at high pressure for 25 minutes. Which is fantastic since they cook along with the potatoes. Or if you are feeling lazy or tired after a long day, go for canned black beans. They are harder to find in Germany, but can be found at specialty stores and some organic food stores. Look for the Italien label "Probios Bio Organic Fagioli Neri al Naturale" or black beans from Amaizin or Rapunzel.