Kwati

Two causes dominate: old seeds that will never germinate, and a cloth that is either too dry or soaking wet. The cloth should feel damp without the beans sitting in water, and they need rinsing daily. If nothing happens, soak twelve hours longer and cook them unsprouted; the stew is still good, only denser.

Yes, what matters is mixing beans of different sizes and textures, peas, beans and lentils together. Choose varieties with similar cooking times, though, or the small lentils collapse while the big beans stay hard. Five or six work perfectly well.

A neutral oil works, but you lose the characteristic pungency. You can recover some of it by popping half a teaspoon of mustard seeds in the neutral oil before the caraway. If you do use mustard oil, heat it until it just smokes before adding the spices, which softens its raw harshness.