In a large skillet, saute onions and garlic in oil until tender. Stir in the broth, parsley, salt, pepper and cumin. Cover and simmer for 2 minutes. Combine cornstarch and apple juice until smooth; pour into the skillet. cook and stir for 1-2 minutes or until thickened.
Stir in the fish, tomato and broccoli. Cover and cook for 2 minutes or until fish easily flakes with a fork. Meanwhile, cook spaghetti according to package directions; drain and toss with olives. Top with fish mixture.