Discard the chickpea soaking water and place in a pot with kombu and water. Bring to a boil on a medium flame.

Skim off any foam that rises as beans boil. Lower the flame to medium low and simmer uncovered for 30 minutes.

Cover pressure cooker, bring to pressure and pressure cook for 1 to 1 1/4 hours.

To make hummus, remove beans from pressure cooker and strain out any remaining cooking liquid and save it.

Puree the chickpeas in a hand food mill or a blender.

Puree the onion, parsley and umeboshi plums or vinegar together with some of the chickpea cooking liquid and add to the pureed beans.

Garnish with chopped scallions and serve with rice, bulgur or cous-cous salad, pita bread, chips, crackers, or as a dip for raw or blanched vegetables.