To make tomato sauce: Sweat bell peppers, onion and garlic in butter until translucent. Crush tomatoes by hand and add to pot with herbs and bay leaf. Let simmer for one hour; season with salt and pepper to taste.
To make shrimp: Combine all spices and toast lightly in sauté pan. Place shrimp in large mixing bowl, coat lightly with vegetable oil and coat liberally with spice blend; let marinate for 6 hours to overnight. In sauté pan, sear each shrimp in vegetable oil on one side, flipping shrimp after 1 to 2 minutes. Cover with tomato sauce, cooking in tomato sauce until shrimp are cooked through and sauce is hot.
To make grits: Combine grits with vegetable stock in medium saucepot. Place on medium heat, stirring often until all liquid is absorbed. Place in heavy cream and butter and continue to stir until all liquid is absorbed. Season with salt and pepper to taste.