Peel and Slice Eggplants: Hold each eggplant by the stem and peel the skin. Cut off the stem. Slice the eggplants into 10–12 mm thick slices.
Salt the Eggplant Slices: Place the slices flat in a large bucket or container. Sprinkle a generous amount of rock salt over the slices. Cover with a tea towel and place a heavy object on top to press the eggplants and help release moisture. Leave at room temperature overnight (about 24 hours).
Prepare Blanching Water: Bring a large pot of water and white vinegar to a boil using a ratio of 3 parts water to 1 part vinegar (e.g., 6 liters water to 2 liters vinegar).
Blanch Eggplant Slices: Drain the salted eggplant slices using a colander. Once the water is boiling, blanch the eggplant slices for 30 seconds to wash them and impart a slight vinegar flavor without cooking them.
Drain and Press Eggplants: Drain the blanched eggplants again in a colander. Place a heavy weight on top to squeeze out remaining moisture and let sit for 5 minutes.
Dry Eggplants: Spread the eggplant slices flat on a clean surface. Cover with a clean towel or blanket and let dry for about 6 hours.
Prepare Flavoring Ingredients: Chop chilies (optional) and garlic into small pieces. Gather fresh oregano sprigs and basil leaves.
Layer Eggplants in Jars: Place a layer of eggplant slices flat in jars. Sprinkle half a spoon of garlic, half a spoon of chilies, some oregano, and a few basil leaves. Repeat layering about 5-6 times, finishing with eggplant on top.
Add Olive Oil and Seal: Top the layered eggplants in the jars with extra virgin olive oil, ensuring the eggplants are fully covered. Use sticks or similar to keep eggplants submerged and firm. Let the oil penetrate for about 10 minutes before closing the jars tightly.
Storage and Serving: Store the jars at room temperature. The marinated eggplants can be eaten immediately but improve with time. They keep up to one year if properly sealed and covered with oil. Serve as a side dish, in salads, or in sandwiches.