In a large skillet, saute onion and green pepper in oil until tender. Add garlic; saute 1 minute longer. Stir in the tomato sauce, tomatoes, olives, cumin, pepper sauce and pepper. Bring to a boil. Reduce heat; simmer, uncovered, for 5 minutes.
Add fillets. Cover and cook over medium heat for 10-14 minutes or until fish flakes easily with a fork, turning once.