For the sauce, except for eggplants and Mozzarella cheese, mix the rest of the ingredients and seasonings in a large bowl. Add more sea salt, ground black pepper or sugar if necessary. (As for basil, I can image that 1 tablespoon of dried basil to work totally fine for the sauce instead of fresh basil.)
Cut the eggplants into slices, about 1/8 inch thick per slice.
Preheat your oven to 375°F.
Now the fun part starts… Use a spoon to set one thin layer of the sauce on the bottom of a medium baking bowl (mine is 8×8 inch).
Lay eggplant slices flat on top of the first layer of sauce.
Spread another layer of sauce on the eggplants. Make sure the eggplant slices are all covered by the sauce.
Sprinkle one layer of Mozzarella cheese.
Repeat step 5-7 until all the eggplant slices are nicely set into your baking bowl. Evenly spread the rest of the sauce and sprinkle the remaining cheese on top. (It’s like building a wall!)
Place the baking bowl at lower rack of the preheated oven. Bake for 40 minutes.
After done, let the Eggplant Casserole sit for 5 minutes before serving.