In a medium saucepan, bring 3 cups water to a boil, and stir in the couscous. Remove from heat, cover, and let sit 5 minutes.
Heat the olive oil in a skillet over medium heat, and saute the onion about 5 minutes, until tender. Mix in the garlic, and continue to cook and stir about 2 minutes. Mix in the artichoke hearts with reserved liquid, capers with reserved liquid, and olives. Stir in the tomatoes, wine, lemon juice, and water (enough to attain desired thickness). Season with sumac powder, red pepper, basil, cumin, ginger, and pepper.
Bring the mixture to a boil, and mix in the fish chunks. Reduce heat, and simmer 10 minutes, or until the fish is easily flaked with a fork. Serve over couscous.