Preheat oven to 375 degrees F. Poke the eggplants all over with a fork and place on foil, on baking sheet, and roast for 45 minutes. Let cool for about 10 minutes, then halve the eggplants vertically, scoop out the flesh and put in a fine mesh strainer. Press out and drain juice that will come out. Then place flesh into a food processor or blender. Discard the skin.
Add tahini, lime juice, garlic, coriander, and salt. Blend until completely smooth, about 2 minutes. To serve, garnish with the mint and olive oil.
This recipe is lightly adapted from the cookbook Vegetarian Heartland by Shelly Westerhausen.