Melt 1 tbsp butter in large skillet over medium heat. Add shrimp, onion, and celery. Cook, stirring occasionally, until shrimp turn pink. Drain excess water from cooking shrimp. Remove from heat and set aside. Coarsely chop shrimp once they have cooled off.
Melt 4 tbsp butter in dutch oven over medium heat. Stir in flour. Gradually add chicken broth, stirring constantly. Add ketchup, bay leaf, and Creole seasoning and stir to combine. Bring to a boil, reduce heat to low and cook another 5 minutes.
Add shrimp, onion, and celery mixture and cook another 10 minutes. Discard bay leaf. Stir in half and half and heat through for a couple minutes on low.