For Shrimp Creole: In a large saucepan, melt butter over medium heat. Add onion, garlic, celery, green pepper, and a pinch of salt and cook, stirring, until wilted, about 7 minutes.
Add tomatoes, bay leaves, cayenne and thyme and bring to a boil. Reduce heat to medium-low and simmer, uncovered, for 30 minutes.
Whisk together flour and water in a small bowl. Stir into tomato mixture and continue to cook for about 5 minutes, stirring.
Add shrimp, Worsterschire sauce, hot sauce, and lemon juice and cook for about 5 minutes until shrimp turns pink and begins to curl. Add chopped parsley and season to taste with salt, pepper, and more hot sauce, if desired. To serve, spoon over grits and garnish with freshly chopped parsley.
For Cheddar Grits: In a medium saucepan, bring water to a boil with a pinch of salt. Once boiling, whisk in grits, thyme, and rosemary and reduce heat to low. Cover and cook, stirring occasionally, for 15 minutes. Whisk in cream and cheddar cheese and season to taste with salt and pepper. Return lid to pot and continue to cook until grits are tender and liquid has evaporated.