Look for light, airy, torpedo shaped eggplants, with slick skin, homogenous in color. If it’s light as a feather, medium sized and long, than there’s a good chance it’s good.
Put it on fire. Wash and wipe dry the eggplant, then put it on a stove (or any other source of open fire). Do NOT cut or pierce the skin – leave it perfectly unharmed. This way, it’ll stay light in color and taste. Also, the whole process will be WAY less messy.
Use tin foil to keep your stove clean: take off the stove-top, cover with a large piece of tin foil, carefully shape a hole for the stove-top and put it back.
Roast completely. It is actually easier to not roast the eggplant for enough time than to over-roast it. Leave it there for at least 10 minutes, and turn it over every couple of minutes. Don’t take it off the stove before the skin looks like a burnt paper. It may drip some fluids during the process, and that’s perfectly OK.
Take it off the fire. When the eggplant is perfectly burnt and very soft, take it off the stove and put it in a large bowl to chill a little. Then cut it in two and put over a strainer and let the rest of the fluids to drain for at list half an hour. If you want your roasted eggplant in one piece, wear rubber gloves and peel it gently over the strainer.
When your eggplant is roasted, chilled and drained, you can empty it’s content with a spoon (if you didn’t peel it).
You don’t even have to make Baba Ganouj out of it – sprinkle some salt and pepper, squeeze a lemon, crush some garlic and pour a little olive oil over it, and serve it with good bread. Everyone who’d eat this will worship you.