Warm up grill to high heat. Pierce eggplants several times with a sharp knife. Place on the grill and cover. Cook, turning occasionally until blacked all over and eggplant skin is very soft (20 minutes or so). Remove from grill and cool.
Halve eggplants lengthwise. Scrape the flesh into a colander and let drain. Discard the skins.
Blend tahini, lemon juice, garlic, cayenne, salt and pepper in food processor until smooth. Add eggplant and continue to process until mixture is smooth.
Scoop into serving dish. Drizzle with good olive oil and garnish with parsley or Kalamata olives.