Melt 2 tablespoons butter in medium skillet; blend in 2 tablespoons flour. Add onion, celery, bell pepper and garlic; cook and stir over medium-high heat 5 minutes or until vegetables are tender and flour mixture is lightly golden.
Stir in tomatoes and Hot Sauce. Heat to boiling. Reduce heat to medium-low. Cook, uncovered, 5 minutes or until slightly thickened. Stir occasionally. Add shrimp. Cook 5 minutes or just until shrimp are pink. Serve over rice. Garnish with chopped parsley, if desired.