Combine ingredients for sweet ‘n sour sauce in a bowl, and set aside. Heat oil in a skillet over medium-high heat. Add broccoli, carrots, cauliflower, and celery; cook for 2 minutes. Add bell pepper and sugar peas, and cook for an additional 2 minutes. Add sweet ‘n sour sauce, bring to a boil, cover, and simmer for an additional minute. Serve vegetables while hot. Yield: 4-6 servings.