We make a parmigiana with four layers of eggplant slices, and the last layer has more sauce, parmesan, and mozzarella than the other layers. Keep this in mind when you add the sauce and the cheese.
Add just a bit of tomato sauce to a large baking dish or casserole (9 x 13 inches | 23 x 33 cm).
Add the first layer of eggplant slices. Arrange them tightly but without overlapping. Cut the slices with scissors if they are too large.
Cover with a ladleful of tomato sauce and spread it with a spoon.
Drizzle with a couple of handfuls of finely grated parmesan cheese, a sprinkle of grated or chopped mozzarella cheese, and a handful of basil leaves.
Cover with the second layer of eggplant slices, this time arranged in the opposite direction.
Add a ladleful of tomato sauce, then parmesan, mozzarella, and basil like before.
Repeat with two more layers of eggplant (4 eggplant layers in total).The last layer should have more tomato sauce, parmesan, and mozzarella than the other layers. Do not add basil on top.