Place the liver, whole eggs and one onion into a large saucepan with the water. Bring to a boil and stir in the chicken stock cubes. Simmer for one hour then allow to cool.
Meanwhile heat the oil in a large frypan over medium heat. Chop one onion and fry in the oil until tender. Chop the third onion and set aside. When the liver has cooled grind together the liver, hard-cooked eggs and the three onions. Season with salt and pepper. Chill before serving.