Combine the first 4 ingredients in a jar. Cover tightly, and shake vigorously.
Bring 1 1/2 cups water to a boil in a medium saucepan; gradually stir in couscous. Remove from heat. Cover and let stand 5 minutes. Fluff with a fork. Combine couscous, bell pepper, and remaining ingredients in a large bowl. Add the dressing mixture. Toss couscous mixture gently to coat.