Cut pork into 1/2-in. x 1/2-in. x 2-in. strips. In a large resealable plastic bag, combine cumin, pepper and salt if desired. Add pork; seal bag and shake to coat.
In a large skillet coated with cooking spray, stir-fry pork and garlic over medium heat until pork is browned. In a bowl, combine broth, orange juice, vinegar and brown sugar; mix well. Add carrots and 1-1/2 cups of the broth mixture to skillet; bring to a boil. Reduce heat; cover and simmer for 5 minutes or until carrots are tender.
Combine cornstarch and remaining broth mixture until smooth; add to skillet, stirring constantly. Bring to a boil; boil and stir for 2 minutes. Add green onions; cook for 1 minute. Serve over noodles if desired.