1. In a large frying pan, heat margarine and oil over moderate heat. 2. Add onion and cook slowly, stirring occasionally, until onions are soft and a deep, dark brown (This may take 30-40 minutes). Remove onions from pan with slotted spoon and set aside.3. Turn the heat to moderately high. Add chicken livers and saute in remaining fat until quite firm and very well browned.4. Add salt, pepper and sugar, and cook a few more minutes. 5. Remove from heat and cool slightly. 6. Grind onions, chicken livers and hard-boiled eggs through a meat grinder, adding all scraped bits and fat from pan. Mix thoroughly. 7. If mixture is slightly crumbly, add one tablespoon additional chicken fat and blend well. If the liver tastes too bland, add a bit more salt.8. Chill and serve with crackers, or challah on Shabbat, or matzo on Passover.