Peel and devein the shrimp, leaving only their tails attached. Reserve the shells separately.

Sprinkle the shrimp with 1 tablespoon of the Essence and 1/4 teaspoon of the pepper. Toss to coat the shrimp well and refrigerate the shrimp until you have made the sauce.

Have the Rosemary Grit Cakes out of the refrigerator and on a baking sheet, per recipe instruction, ready to go in the oven.

To make the sauce, heat 1 tablespoon of the oil in a large pot over high heat. When the oil is hot, add the onions and garlic and sauté for 1 minute. Add the reserved shrimp shells, the remaining Essence, the bay leaves, lemons, water, Worcestershire, wine, salt, and the remaining ¼ teaspoon black pepper. Stir well and bring to a boil. Reduce the heat and simmer for 30 minutes. Remove from the heat, allow to cool for about 15 minutes, and strain into a small saucepan. There should be about 1½ cups. Place over high heat, bring to a boil, and cook until thick, syrupy, and dark brown, about 15 minutes longer. You should have 4 to 5 tablespoons of barbecue sauce base.

When you are ready to serve the shrimp, preheat the oven to 500ºF and cut and finish cooking the grit cakes. Set cakes aside, loosely covered in a warm oven until ready to serve.

Heat the remaining 1 tablespoon of oil in a large skillet over high heat. When the oil is hot, add the shrimp and quickly sauté, occasionally shaking the skillet, until almost cooked through, about 2 minutes. Add the cream and all of the barbecue base. Stir and simmer for 3 minutes. Remove the shrimp to a warm platter. Cook the sauce until it is thick enough to coat the back of a spoon, 4 to 5 minutes longer. Whisk the butter into the sauce. Remove from the heat.

To serve, place one grit cake (or two, if you make them small) in the center of each dinner plate. Spoon the sauce and the shrimp over and around the grit cake(s) and garnish.