Heat oven to 350°F. Spray 11x7-inch (2-quart) glass baking dish with cooking spray. Cook and drain pasta shells as directed on package.
Meanwhile, in 10-inch skillet, heat oil over medium heat until hot. Cook stir-fry vegetables and garlic in oil 2 to 3 minutes, stirring occasionally, until crisp-tender. Add zucchini; cook 4 minutes, stirring occasionally.
Stir in olives and 1/4 cup of the pasta sauce. Cook until hot, stirring frequently. Remove from heat.
In medium bowl, mix ricotta cheese, egg, Parmesan cheese and 1/2 cup of the shredded cheese blend. Stir in zucchini mixture until well mixed.
Fill each cooked pasta shell with about 2 tablespoons zucchini mixture. Place in baking dish. Pour remaining pasta sauce over shells.
Cover with foil; bake 30 minutes. Sprinkle with remaining 1/2 cup shredded cheese. Bake uncovered 5 to 10 minutes longer or until bubbly and cheese is melted.