Lemon Couscous & Mahi Mahi

1/2 C sliced onion, separated into rings
1/2 C white wine
1/4 C lemon juice
1/2 tsp grated lemon rind
1/8 tsp salt
Freshly ground black pepper to taste
1 lb mahi-mahi or other mild fish
1 C water
1 C uncooked couscous
1 small can tomatoes, drained, chopped
4 lemon slices, for garnish
2 T chopped fresh parsley

Sauté onion in margarine over medium-high heat for 1 to 2 minutes. Stir in wine, lemon juice, lemon rind, salt, and pepper. Bring to a boil; add fish. Cook, covered, over medium-high heat for 8 to 9 minutes, or until fish flakes easily with a fork. Remove fish and onion rings from skillet; keep warm. Add water to cooking liquid to make 1-1/2 C; bring to a boil. Stir in couscous and remove from heat. Cover; let stand 5 minutes. Stir in tomatoes and juice of 1 lemon.

Serve couscous with fish and onions, garnished with lemon slices and parsley.