Turn a grill on high. Slice the eggplant into quarter inch pieces (about 20 pieces. It's your preference if skin is left on or off.) Brush eggplant with olive oil. Season with salt. Grill eggplant pieces about 7 minutes per side or until nicely charred and tender.
In a saucepan heat tomato sauces until bubbly.
Preheat oven to 400 degrees F. In a 9x13-inch pan, layer the sauce, eggplant pieces, cheeses, and breadcrumb in this order: 1/3 sauce, 1/2 eggplant, 1/3 sauce, 1/2 mozzarella cheese, breadcrumbs, the rest of the eggplant, the rest of the sauce, the rest of the mozzarella, and all of the parmesan cheese. Add pepper to taste.
Bake uncovered for about 30 minutes or until the sauce and cheese slightly bubble. Remove from heat and let stand for 5 minutes. Enjoy with a side of delicious garlic bread!