Rinse the chick-peas. Cover with plenty of water in a large pan, bring to the boil and skim until clear. Cover and cook until soft: in a pressure cooker they will take 15-20 minutes; otherwise a little over 1 hour, according to their age. Strain the chick-peas, reserving the cooking liquid. Divide all the ingredients in two and place the first batch in a food processor or liquidiser; blend until grainy and of a runny consistency. If too dry, add more of the reserved cooking liquid and then adjust the seasoning and blend it in briefly. Make the second batch in the same fashion. Pour onto a flat platter, and sprinkle the oil and the cayenne pepper or paprika decoratively on top before serving.