Season the shrimp with salt and pepper. Set aside while you begin the grits.
In a medium saucepot with a lid, combine the stock, milk, garlic, and salt and pepper to taste. Don’t oversalt because your cheese will bring an element of salt at the end.
Bring to a gentle simmer over medium-high heat.
While whisking with one hand, slowly pour the grits into the pot with the other hand. Whisk to remove any lumps.
Lower the heat to low and place the lid on the pot. Cook the grits for about 20 minutes, stirring about halfway through cooking, until they are thick and creamy.
Remove the pot from the heat and add the cheese by handfuls, stirring well to incorporate and melt the cheese before adding another handful. Continue until all the cheese is melted into the grits. Keep warm with the lid slightly ajar.
Add all the Sauce ingredients in a 2-cup measuring cup or medium bowl. Set aside.
Cook the bacon over medium-high heat until crispy. Remove it with a slotted spoon to a paper towel-lined plate or bowl. Set aside. Drain off most of the bacon grease into a clean, small bowl, leaving about 2 tablespoons in the pan. Reserve grease in the bowl. You’ll use this as you continue to cook.
Maintaining your heat, cook the sliced sausage on both sides until browned. Remove them to a paper towel-lined bowl plate or bowl. Cook in batches if necessary.
Add another tablespoon or two of grease if necessary to cook the shrimp.
Add the shrimp in batches and cook on both sides just until cooked through. Remove to a plate or bowl.
Add another tablespoon of bacon grease to the hot pan. Add the onions and peppers. Cook, stirring frequently, until softened and lightly caramelized.
Add the garlic, herbs, and tomato paste. Stir constantly for about 20 seconds.
Stir the Sauce again and add to the pan. Add the butter and heat through to melt.
Add the sausage and shrimp back to the pan. Stir everything together and heat through.
If your grits have cooled and thickened, rewarm over medium heat. Add chicken stock or milk to loosen, as needed.
To serve, place grits in a serving bowl. Top with the shrimp and veggie mixture, bacon, and green onions, and hot sauce if desired.