Build a small fire in the grill. Whe the coals are very hot, throw some grape vine or other fruit cuttings on them and place the eggplant right in the flames. Leave them there until the side touching the coals is black, which will take 8 to 10 minutes. Turn the eggplant and leave them on the fire until they are black all over, another 8 to 10 minutes. Remove the eggplant and let them sit until they are cool enough to handle, then scoop out all the flesh.