Lower oven temperature to 350 degrees F. In an 8 by 12-inch brownie pan, place the 4 largest eggplant slices evenly spaced apart. Over each slice, spread 1/4 cup of tomato sauce and sprinkle with a teaspoon of basil. Place one slice of mozzarella over each and sprinkle with 1 teaspoon grated Parmigiano. Place the smaller slices of eggplant over each of the disks and repeat with tomato sauce, basil, and the 2 cheeses. Repeat the layering again until all the ingredients are used.