Fry eggplant in one cup of olive oil until browned. Remove from skillet. Add onions, browning gently over medium heat in 1/2 cup of pine nut oil. Add tomato sauce and celery and cook until tender. Add capers, olives and pine nuts, and the fried eggplant. Heat wine vinegar and sugar until dissolved. Add this to eggplant mixture. Add salt and pepper to taste. Allow to simmer until flavors mix. Serve bruschetta style on toast points or topped over pasta. Caponata will keep up to two weeks in the refrigerator.