Peel and devein shrimp, pat dry, and season one side with salt, pepper, and 1 Tbsp Cajun seasoning
Bring chicken stock to a boil and add grits. Bring back to boil and turn heat to low simmer. Cook for 25 minutes, or to just short of desired thickness stirring often to avoid sticking.
Turn heat off of grits, stir in cheese, and cover until everything is ready
While grits are cooking, heat a large nonstick on medium, add butter and 1 ½ tsp olive oil
When butter has melted, add shrimp in a single layer with seasoned side down, season second side with more salt and pepper, 1 Tbsp Cajun seasoning, and half the garlic
Cook shrimp until just pink on both sides, about 2 minutes each side, and remove to a plate and set aside
Add remaining olive oil, and bacon grease to the pan.
Once bacon grease has melted, add onion and green pepper; cook until softened, about 8 minutes
Once softened, add garlic and cook until fragrant
Add tomatoes, shrimp stock, and remaining Cajun seasoning. Bring to a boil and simmer until volume has reduced by half.
Add shrimp back and any accumulated juices. Heat for a minute or two to finish cooking the shrimp.
Spoon ¼ of the grits onto a plate, and top with ¼ of the shrimp