Drain the beans, cover with fresh water & bring to a boil. Boil hard for 10 minutes, reduce heat, cover & simmer until tender, about 2 hours, depending on the age of the beans. Drain & set aside. When cooled, mash.
Heat olive oil & saute the onions until very soft, 10 minutes. Add to the mashed soya beans. Stir in the tomato paste, olives, parsley, salt if necessary (remember that the olives already add a salty flavour to the rest of the ingredients) & sesame seeds.
Spoon into a serving dish & chill for at least 30 minutes before serving. Serve with crackers or toast sliced into fingers.