Cook peas in boiling water to cover 30 seconds; drain. Plunge into ice water to stop the cooking process; drain.
Combine peas, spinach, water chestnuts, and shredded carrots in a large bowl; set aside.
Cook scallops in hot olive oil in a wok or heavy skillet over high heat until lightly browned, turning once. Set aside.
Combine tamari and next 5 ingredients, stirring until blended; drizzle over vegetable mixture, tossing gently. Top with scallops.