Preheat oven to 425°F (220ºC). Place eggplants, cut-side down, on parchment paper-lined baking sheet. Bake until eggplant is tender and skin can be easily pierced with a knife, about 40 min. Set aside until cool enough to handle, about 20 min.
Scoop eggplant flesh into bowl of food processor (discard skin) and add tahini, lemon juice, olive oil, garlic, salt and pepper. Blend until completely smooth.