Step 1

Preheat the oven to 425 degrees and line 3 sheet pans with parchment paper. (You may have enough eggplant to make a 4th pan.)

Step 2

Brush the eggplant slices lightly with olive oil on both sides, then lay them out in an even layer on the sheet pans.

Step 3

Sprinkle with salt, then bake until golden brown, rotating the pans as needed, about 15-20 minutes. Use a pair of tongs to flip the eggplant over to the other side and continue cooking for abutter 10-15 minutes or until golden brown. Keep an eye on the eggplant as it cooks. Some pieces may brown before the others - remove them and continue cooking.

Step 4

Lower the oven to 350 degrees and set aside 2 cups of mozzarella and 1/2 cup pecorino Romano.

Step 5

Ladle about 1/2 cup marinara sauce into the bottom of a 9×13 inch casserole dish, then spread it around to coat.

Step 6

Place a single, even layer of eggplant over the sauce, then top with another thin layer of sauce and a sprinkling of each cheese.

Step 7

Continue layering the eggplant with more sauce and more cheese until you’ve used everything up. It's okay if the final layer of eggplant is a bit sparse. Sprinkle the top with the reserved 2 cups mozzarella and 1/2 cup pecorino Romano.

Step 8

Cover with foil and bake for 40 minutes, then remove the foil and bake until bubbling and lightly golden on top, about 20 minutes more.

Step 9

Let cool for at least 30 minutes before serving. Sprinkle with chopped parsley or basil if desired. Leftovers can be stored in the refrigerator for up to 5 days.