Rinse and trim the eggplant and cut lengthwise into slices. Lay the slices side by side in a baking dish and shower with salt. Leave to infuse for 15-20 minutes.
Pat the eggplant slices dry with kitchen towels and sauté in 8 tablespoons of olive oil in a large, non-stick pan until lightly browned. Drain briefly drain on kitchen towels.
Peel and dice the onion. Peel the garlic and cut into thin slices.
For the dressing, mix the vinegar with the remaining olive oil and season with salt and pepper.
Arrange the eggplant slices on plates like a fan. Distribute the onion, garlic and olives over them and drizzle with the dressing. Leave to marinate for 15 minutes.
Serve seasoned with freshly ground pepper and garnished with parsley leaves.