Meanwhile, coat an unheated large nonstick skillet or wok with cooking spray. Preheat over medium-high heat. Add sweet pepper, onion, and celery to hot skillet. Cover and cook for 3 minutes, stirring occasionally. Add apple, water chestnuts, carrot, ginger and garlic; cover and cook for 3 to 4 minutes more or until vegetables and apple are crisp-tender, stirring occasionally. Remove vegetable mixture from skillet.