Cut the eggplant into ¾ inch thick slices. You want slices that are not too thin but also not too thick. See image for reference.
In a large mixing bowl, place the water, oil and salt. Place all the eggplant slices into the bowl and toss. Let it sit like that, and toss every now and then, for an hour to two. The eggplant will release the bitter juices and soften.
Preheat oven to 400°F. Remove water from the bowl. Line a baking sheet with parchment paper and drizzle generously with oil. Place all the eggplant slices in one layer. Drizzle with some more oil.
Bake uncovered for 20 minutes or until golden, then turn over each piece and return to oven for another 20 minutes or so.