On the net. At least around here this is the norm. The only thing that can go directly on the coals when barbecuing are the potatoes. Plus, a huge improvement in taste for barbecued eggplants is to peel them off as soon as possible (burning hot) and not letting them stay cooked in their peel too long, (They will develop a slightly bitter taste and "rubberized" texture) + never rinse them directly under water once cooked. Only rinse your hands, but not the eggplant directly, it will retain even more water and wash off the taste. (If you roast them whole)