There are 2 ways to cook the eggplants. The first way, on the stovetop, is my favorite because it yields a much smokier-flavored babaganoush.
For the stovetop method: Turn 2 burners up full-throttle. Place 1 eggplant on each burner and, using a pair of tongs, turn every 5 minutes or so, until the entire surface of eggplant is charred and crispy, about 15 minutes. Don't worry if the eggplant deflates a little. Remove from the burner and place on a plate to cool.
For the oven method: Preheat the oven to 450 degrees F. Prick the eggplants all over with a fork (this keeps the eggplant from exploding in the oven, so don't skip this step). Place on a baking sheet and roast until softened, about 20 minutes. Remove from the oven and allow to cool.
Regardless of the cooking method you choose, once the eggplant is cool enough to touch with your hands, carefully peel the charred skin off the eggplant. Discard the skin. Move the flesh onto your chopping board, slice off the stem and discard. Using your knife, mince the flesh until almost smooth. Scoop into a bowl.
Add the lemon juice, tahini, parsley, and a little salt and pepper. Whisk together and taste for seasoning. Feel free to add more lemon juice, more salt and pepper... it will vary depending on the size of your eggplant, and how you like your 'ganoush! Serve with pita chips.