Preheat your oven to 475 degrees Fahrenheit.

Use a paring knife to pierce the eggplant in several places to allow the steam to escape. Bake eggplant in a shallow  baking dish until skin is dark brown, turning it occasionally, unitl it has collapsed, about 40 to 45 minutes.

When it is cool, remove the peel by tearing it away from the flesh. Remove any long strands of seeds. Discard seeds and any juices.

Put eggplant in food processor and blend until smooth. Stir in onion, olive oil, lemon juice, salt, pepper and sugar. Transfer to a bowl and chill.