Place chicken and soy sauce in a shallow dish or heavy-duty zip-top plastic bag. Cover or seal, and chill 15 minutes.
Cook broccoli in boiling water 3 minutes; drain. Plunge into ice water to stop the cooking process; drain. Set aside.
Drain chicken, reserving soy sauce; dredge chicken slices in cornstarch.
Brown chicken, in batches, in a large nonstick skillet coated with cooking spray over medium-high heat 1 minute on each side or until done. Remove chicken from skillet, reserving drippings in skillet; keep chicken warm.
Add reserved soy sauce, onion, and next 5 ingredients to reserved drippings in skillet; sauté 2 to 3 minutes or until vegetables are tender.
Add chicken broth and marmalade, stirring until marmalade is melted. Return chicken to skillet. Bring to a boil; stir in broccoli and orange sections, and serve immediately.