If using chicken strips, pour oil into a wok or large skillet. (Add more oil as necessary during cooking.) Preheat over medium-high heat. Stir-fry chicken, half at a time, about 3 minutes or till no longer pink; remove. (Do not stir-fry canned chicken.) Break up noodles (set flavor packet aside). Add noodles, 1 cup water, zucchini, celery, and garlic to wok. Bring to boiling; reduce heat. Cover; simmer 3 to 5 minutes or till noodles and vegetables are tender. Stir in cooked or canned chicken, the packet contents, sweet-and-sour sauce, and peanuts; heat through. Top each serving with oranges.