For shrimp: Melt butter in a large skillet, add onion, celery and garlic, and cook until onion is soft, but not transparent. Blend in flour, salt, sugar, hot pepper sauce, paprika and bay leaf. Add tomatoes and green pepper, and simmer for 5 minutes. Add shrimp and stir until shrimp are pink, about 5 minutes. Remove bay leaf.
For rice: In a medium saucepan, bring water to a boil. Add butter, salt, and rice. When mixture boils again, reduce heat to low and cook covered until liquid is absorbed. Add cheese and mustard. Combine with shrimp mixture after cheese melts.
Note: The shrimp mixture will at first appear watery and the rice will appear too sticky. They combine, however, to form a marvelous texture and flavor.