Sprinkle round steak with salt and pepper. Spray 12-inch nonstick skillet with nonstick cooking spray. Heat over high heat until hot. Add steak; cook 1 to 2 minutes on each side or until browned.
Add celery, carrots, fennel, potatoes, parsnip and onion; cook and stir 1 minute. Add broth and thyme; bring to a boil. Reduce heat to low; cover and simmer 30 to 40 minutes or until vegetables are tender.
In small bowl, combine water and cornstarch; blend well. Uncover skillet. Stir in cornstarch mixture; cook an additional 2 to 3 minutes or until sauce is thickened, stirring constantly. Stir in lemon peel.