Cook and drain pasta as directed on package.
While pasta is cooking, heat oil in 12-inch skillet over medium-high heat. Add chicken and onion; stir-fry 5 to 6 minutes or until chicken is brown.
Add broccoli and peas to chicken mixture. Cook over medium-high heat 4 to 5 minutes, stirring frequently, until vegetables are crisp-tender.
Stir together broth, thyme, lemon peel, cornstarch and lemon pepper in small bowl; stir into chicken mixture. Cook over medium-high heat 1 to 2 minutes or until sauce is thickened and vegetables are coated.
Stir in tomatoes; cook until thoroughly heated. Serve over pasta.