Before beginning to cook, marinate chicken in 1/4 cup Asian marinade in plastic food-storage bag in refrigerator for as long as possible, depending on your schedule (as long as overnight).
Once chicken has marinated, in saucepan, heat the water to boiling. Add rice and salt. Cover; simmer over low heat for 20 to 25 minutes or until liquid is absorbed. Remove from heat. Fluff rice with fork; let stand, covered, 5 minutes.
After rice has cooked 5 minutes, in large skillet, heat stir-fry oil over high heat. Add chicken and any marinade from bag to the skillet; stir-fry 3 minutes or until outsides are lightly colored. Add bok choy, carrots and scallions; cook until carrots are crisp-tender, about 8 minutes. Stir in water chestnuts; heat through.
Meanwhile, in small bowl, whisk Asian marinade and peanut butter. Once vegetables are cooked, reduce heat to medium. Stir in peanut butter mixture; cook, stirring, 1 minute or until chicken and vegetables are coated. Remove skillet from heat.
Stir peanuts and scallions into rice. Transfer to serving platter; top with chicken mixture. Serve warm. Makes 6 servings.