Cook pasta according to package directions; drain and set aside. In a small bowl, combine the cornstarch and bouillon granules; stir in the water and soy sauce and set aside., In a nonstick skillet, stir-fry mushrooms in 1 tablespoon oil 3 minutes or until tender; remove and keep warm. In same pan, heat remaining oil. Add remaining vegetables; stir-fry 5 minutes or until crisp-tender. , Stir soy sauce mixture and add to the pan. Bring to a boil; cook and stir for 2 minutes or until thickened. Add pasta and mushrooms. Heat through.,