In a small skillet, saute the onion, celery and green pepper in oil until tender. Add the garlic; cook 1 minute longer. Add the broth, tomato paste and seasonings. bring to a boil. Reduce heat; simmer, uncovered, for 5 minutes or until heated through. Stir in tomato.
Arrange fillets in a greased 13-in. x 9-in. baking dish; top with vegetable mixture. Bake, uncovered, at 375° for 15-20 minutes or until fish flakes easily with a fork. Serve over rice; sprinkle with parsley.