Arrange sliced eggplant (4 pounds) onto a flat surface and sprinkle both sides generously with kosher salt.
Arrange one layer of salted eggplant about the size of a paper towel, then lay 2 paper towels on top. Place another layer of salted eggplant on top of that, then another 2 paper towels, and so on until you have stacked all the eggplant. Let eggplant sit until it has released excess liquid, 1 hour. This step gives the eggplant a creamy texture when baked.
Once liquid has been released and soaked up by the paper towels, remove the paper towels and gently wipe away some of the salt on the surface of the eggplant.
Heat a large pan with a good nob of olive oil. Add the eggplant and fry on each side until nicely browned, about 4 minutes per side.
Once cooked, remove and set aside. Preheat the oven to 350°F or 180°C.
In a large baking casserole dish, ladle a thin layer of sauce onto the bottom. Arrange cooked eggplant on sauced dish so that they have about 1cm between them. Top each eggplant with a tablespoon of sauce and a shred of the fresh mozzarella cheese. Layer another eggplant slice, tablespoon of sauce, and shred of mozzarella on top. Add one more layer in this order.
Bake for 30 minutes, uncovered. When you have 5 minutes left on the timer, turn oven setting to "broil" or whatever its warmest setting is. Keep an eye on the eggplant to make sure it doesn't burn. Let cool for about 10 minutes and enjoy with pasta.