For the Grits:
Put water in a large pot and bring to a rolling boil. Add salt and slowly sprinkle in grits while stirring with a wooden spoon, then add the half-and-half and return to a simmer.
Cook the grits slowly, over low heat for 30-40 minutes until most of the liquid has been absorbed. Stir in butter, Tellicherry black pepper and Voodoo. Continue to cook grits until they are smooth and creamy. Hold covered, in a warm spot, while you finish preparing the shrimp and sauce.
For the Sauce:
In a heavy saucepan, heat 1 tablespoon of the oil over medium heat and brown the andouille sausage. Once the sausage begins to brown, about 3-4 minutes, remove from pan and set aside.
Season both sides of the shrimp with a sprinkle of Voodoo and sear over medium high heat for about a minute on each side, working in batches to not crowd the pan. Remove from pan and set aside. Add the remaining 1 tablespoon of oil to pan. Add cooked sausage, onion, pepper, garlic, and spices. Sauté for 3 minutes, until the onion is tender and translucent.
Add stock and bring to a boil, gently scrape the bottom to remove any flavorful bits on the bottom of the pan. Reduce heat and slowly add the cream. Bring up to a simmer and allow to reduce until sauce begins to thicken slightly, about 10 minutes.
Once thickened, add seared shrimp and simmer until the shrimp are just cooked, about 2-3 minutes.
When the sauce is finished, rewarm the grits and serve in a shallow bowl with the sauce spooned over the grits. Finish with Voodoo to taste.