Wash eggplant, place in baking pan and bake in at 375F for about one hour, or until soft when pierced with a fork and the eggplant has sort of collapsed into itself.
allow the skin to turn black and charred so as to give a smoky flavour to the salad (you can also grill the eggplant by putting them directly on the grate- whole- on your bbq. Grill until skin is blackened and charred and eggplant is very soft and starting to deflate. If you use the grill method- leave out the liquid smoke).
Skin eggplant when cool enough for you to stand it and chop in small pieces. Mash it up a bit with a fork.
Mix well with onion, garlic, tahini, oil, vinegar (start with 1 tblsp of vinegar and if you want it sharper, add more, a bit at a time), salt and pepper (to taste).
Note: I kind of beat this around with a fork to incorporate the oil well into the eggplant spread- you don't want it looking oily at all, but creamy.