Preheat the oven to 350 degrees. Cut the eggplant length-wise and place the cut sides down on an oiled cookie sheet. Roast about an hour or until soft and starting to collapse.
Allow to cool enough to handle, and scoop the flesh out into a colander to drain. Place 3/4 of the eggplant into a food processor with the garlic, lemon juice, tahini and salt. Blend until smooth or desired texture.
Mash the remaining eggplant, leaving some chunkiness to it. Combine the blended mixture with the chunkier eggplant, drizzle with olive oil, stir, and taste for salt.