In a non-stick pan, bring 4 cups of water to a rolling boil over medium-high heat. Whisk in 1 teaspoon of kosher salt and 1 cup of coarse grits, then reduce the heat to low. Let the grits simmer gently for 35-40 minutes, stirring frequently to prevent sticking.

In a Dutch oven, melt 2 tablespoons of unsalted butter and 2 tablespoons of olive oil over medium heat. Sauté 3 cloves of minced garlic, 1 finely chopped sweet onion, 1 cup of diced celery, and 1 cup of diced red bell pepper until softened, about 5-7 minutes.

Whisk in ¼ cup of all-purpose flour, cooking until a deep brown roux forms, about 30 minutes.

Stir in 1 tablespoon each of fresh sage and thyme, along with ½ cup of dry sherry and 1 tablespoon of Worcestershire sauce. Gradually add 4 cups of low-sodium chicken stock, whisking until the gravy reaches your desired consistency.

Allow the gravy to simmer for about 15 minutes over low heat. Add 1 pound of large shrimp to the pot, cooking until they turn pink, about 3-4 minutes, and gently fold in 1 cup of jumbo lump crab meat.

Dish the warm, creamy grits into bowls and generously ladle the rich Charleston shrimp and crab gravy over the grits. Serve hot.