Preheat oven to 400ºF.
Lay eggplant slices out on a baking sheet, drizzle with EVOO on both sides and season with salt and ground black pepper. Roast in oven about 15 minutes, flipping halfway through, until the eggplant is tender and golden brown. Remove from oven and let cool.
While the eggplant is roasting, in a medium skillet with 1 turn of the pan of EVOO, brown the sausage, about 5 minutes, breaking it up with a wooden spoon or potato masher as it cooks. Remove from skillet with a slotted spoon to a medium bowl. Let cool then mix in the mozzarella cheese and Parmigiano-Reggiano.