Remove stem from eggplant and slice into 1-inch thick slices.
In a dish large enough to hold the eggplant (like a 9 x 13 baking dish), combine remaining ingredients, and whisk until smooth. add eggplant and rub each slice in the marinade until well coated. Marinate at least 1 hour or up to 24 hours. I think 4 hours of marinating time is ideal.
Heat grill to medium heat. Clean grill grates and rub with oil. Grill eggplant until lightly charred on both sides and tender, about 4 minutes per side.
Remove from the grill, drizzle with olive oil, and squeeze lemon over the top.