Add 1 tablespoon olive oil into large nonstick skillet and heat over medium heat. Add 2 to 3 eggplant slices and cook 3 to 4 minutes on each side, adding more oil as needed and repeating with remaining eggplant slices.
Arrange eggplant on baking sheet. Top with each with tomato slices and mozzarella. Repeat layer and finish with eggplant slice.
It's a bit difficult to give exact measurements as the number of slices that you get from your eggplant will vary. You can adjust to your taste. If you use a thinner eggplant, you can simply make thinner, taller stacks.