Place the eggplant slices in a large bowl and cover with salted water. Place a plate on top of the eggplant, so it stays submerged for at least 15 minutes or up to overnight. Drain and dry the eggplant slices with a paper towel.
Dice the eggplant into small cubes.
Heat 2 tablespoons of olive oil in a large skillet, over medium heat, and sauté the diced eggplant for about 10 minutes or until softened and starting to brown. Remove from heat and transfer to a medium bowl.
Add the remaining ingredients and stir to combine. Transfer to a mason jar or other container with a tight-fitting lid and add more olive oil to cover eggplant, if needed. Marinate eggplant, covered and chilled, at least 4 hours. Bring to room temperature before serving.