IN a medium bowl, combine two tablespoons of the oyster sauce with vinegar, ginger, soy sauce and one clove garlic. Season with pepper, if desired. Add fish, turning to coat. Cover and refrigerate at least a half-hour. In a nonstick skillet or seasoned wok, heat two teaspoons of the oil over high heat. Add remaining garlic, stir fry 30 seconds. Add sprouts, peas, green onions and red pepper. Stir-fry two minutes or until tender-crisp. Stir in the remaining one tablespoon of oyster sauce, sesame oil, sugar and pepper. Remove from skillet and set aside. Drain fish, discarding marinade. Heat remaining oil in same skillet. Add fish and stir-fry about four minutes or until done. Add vegetables. Gently toss. Heat through and serve immediately. Nutritional Information: 429 calories, 42 grams protein, 16 grams carbohydrate, 21 grams fat, 105 milligrams cholesterol and 538 milligrams sodium.