Cook lasagna noodles as directed on package. Drain; place in cold water to cool.
Meanwhile, heat oven to 350°F. Heat oil in large skillet over medium-high heat until hot. Add garlic, broccoli, mushrooms and bell pepper; cook 3 to 4 minutes or until vegetables are crisp-tender, stirring frequently. Remove from heat. If necessary, cut broccoli into smaller pieces.
Beat egg in small bowl with wire whisk. Add ricotta cheese and Italian seasoning; mix well.
Drain cooled lasagna noodles. Spread 1/2 cup of the pasta sauce in ungreased 13x9-inch (3-quart) glass baking dish. Top with 4 noodles, overlapping as necessary, half of ricotta mixture, half of cooked vegetables, half of remaining pasta sauce (about 2 1/4 cups) and 1 cup of the shredded cheese. Repeat layers, starting with noodles.
Bake at 350°F. for 45 to 50 minutes or until hot and bubbly. If cheese is getting too brown, cover baking dish loosely with foil. Let stand 15 minutes before serving.