Bring the water to a boil in a medium saucepan, and gradually stir in couscous and raisins. Remove from heat. Cover; let stand 5 minutes. Fluff with a fork.
Combine orange juice and next 6 ingredients (orange juice through black pepper); stir well with a whisk.
Combine the couscous mixture, juice mixture, chicken, and remaining ingredients in a large bowl, and toss well. Garnish with green onions, if desired.