* This works fine without putting olive oil on the eggplant before roasting; I just prefer the consistency when I use olive oil. What I do is take a plastic bag, dump the peeled eggplant slices in, pour the olive oil in, and shake the bag to coat the eggplant. Then put eggplant on the baking dish and roast.
** If you don't have liquid smoke, this would also be good with about ¼ tsp chipotle or smoked paprika.
*** This dish is traditionally served with the olive oil drizzled on top. Personally, I usually prefer it without.