In a nonstick skillet, saute onion and garlic until tender; remove from the heat. Stir in parsley and orange peel. Place halibut in an 8-inch-square baking dish coated with nonstick cooking spray. Top with onion mixture. Combine orange and lemon juices; pour over fish. Sprinkle with salt and lemon-pepper. Cover and bake at 400 degrees F for 15-20 minutes or until fish flakes easily with a fork.