In a small saucepan, bring the water and a pinch of sea salt to a boil.
Slowly whisk in the stone-ground grits, then reduce the heat to low and cover the pan.
Simmer the grits for 15 to 20 minutes, whisking occasionally, until they reach a creamy consistency.
While the grits cook, heat the olive oil in a large skillet over medium-high heat.
Add the sliced andouille sausage to the skillet and sear for 3 minutes until the edges are crispy and browned.
Stir in the diced onion, green bell pepper, and celery, sautéing for 4 minutes until the vegetables are tender.
Toss the raw shrimp with the Cajun seasoning in a small bowl until evenly coated.
Add the seasoned shrimp to the skillet and cook for 2 to 3 minutes until they turn pink and opaque.
Season the mixture with the remaining sea salt and black pepper.
Spoon the warm grits into a shallow bowl and top with the shrimp, sausage, and vegetable mixture.
Garnish with chopped fresh parsley and serve immediately.