Preheat oven to 350; spray 9"x13" pan with cooking spray and set aside.
Meanwhile, bring pot of water to boil for tortellini.
Over medium heat, heat olive oil in a large skillet; add eggplant,onion and garlic and cook, stirring, until vegetables have softened; about 7 minutes.
Add zucchini, yellow squash, bell pepper, tomatoes, basil, parsley, salt and freshly ground black pepper. Bring to a boil stirring frequently as not to allow to stick to pan; reduce heat to medium-low and simmer about 20 minutes, or until vegetables are tender.
Cook tortellini according to package directions; drain.
Spread cooked tortellini in bottom of prepared pan; spoon hot vegetables over tortellini and sprinkle with Mozzarella cheese.
Bake in 350 degree oven for about 20 minutes, or until hot and cheese has melted.