1. In a large skillet, saute the onion, green pepper, celery and garlic in oil for 6 minutes. Stir in the tomato sauce, chili powder, sugar and cayenne. Bring to a boil. Reduce heat; simmer, uncovered, for 10 minutes. Add shrimp; cook and stir until shrimp turn pink. Serve with rice if desired. Yield: 4 servings.