One day before making the recipe, rinse white beans and chickpeas, add to separate bowls, fill with three times their volume of water and leave to soak overnight.
Heat oil in large pot over medium heat; add onions and cook, stirring frequently, until golden. Add the bulgur and lentils.
Drain white beans and chickpeas and add to pot. Stir in cumin, salt and enough water to reach 4 inches above mixture.
Bring to boil; reduce heat and simmer until beans, chickpeas, bulgur and lentils are tender, at least 1 hour. Season with more cumin and salt to taste.