Add the soaked beans (soaked for at least 48 hours, changing the water every 6 to 8 hours). Let the beans absorb the flavors from the sautéed vegetables, then add about 2 cups of water (480 ml), black pepper, chili pepper (fresh is best, but dried works too), and 1 teaspoon of fine salt.

After five minutes, add some tomato purée (plain is best; check the label). Stir, then add more salt and another 2 cups of water (480 ml). Keep a pitcher of water nearby, as the beans will absorb a lot of liquid.

Add your choice of pasta, keeping in mind the cooking time for the type you use. Cook everything over medium-low heat for about an hour. Before it's done, add another cup of water (240 ml) and another teaspoon of salt. Taste and adjust seasoning as you like; I like it as is.