In bowl, whisk rind, juice, soy sauce, mirin, sugar, ginger and garlic.
Place fish in shallow baking dish. Coat with lime mixture. Cover; refrigerate 15 minutes, turning over after 10 minutes.
Meanwhile, bring large pot of water to boiling.
Heat stovetop grill or grill pan over medium-high heat. Coat with cooking spray. Remove fish from marinade; pour marinade in saucepan.
Grill fish until opaque, 7 to 8 minutes, turning over halfway. Transfer fish to plate; keep warm.
Meanwhile, cook bok choy in boiling water until crisp-tender, 2 to 3 minutes. Using slotted spoon, remove to plate. Cook noodles in same water, following package directions.
Boil reserved marinade 3 minutes. Add pepper strips; cook 1 minute. Stir in scallions.
Serve each piece of fish over 1/2 cup noodles and a quarter of bok choy. Top each with one-quarter of sauce with pepper strips and scallions.
Mirin and rice noodles available from Adrianas Caravan, www.adrianascaravan.com.