Position rack in center of oven and preheat the oven to 350 degrees F. Line a shallow baking dish large enough to hold the 2 sole with aluminum foil and lightly grease . Set aside. In a medium skillet, melt 3 1/2 tablespoons of the butter over medium-high heat. Add the olive oil, and, when hot, add the onion, celery, and bell pepper and cook, stirring, until softened, 2 to 3 minutes. Add the shrimp , 4 teaspoons of the garlic, 1 tablespoon of the Essence, 1/2 teaspoon of the salt, and 1/4 teaspoon of the cayenne pepper , and cook, stirring, for 1 minute. Remove from heat and add the parsley and 2 tablespoons of the green onions and set aside to cool. Once the shrimp mixture has cooled, add 1/2 cup of the bread crumbs, and stir to combine well. Season the inside of each fish with 1/4 teaspoon of the remaining salt and season lightly with black pepper. Divide the shrimp stuffing evenly among the pockets in the 2 sole and fold the top fillets over the stuffing so that it is mostly enclosed. Top with lemon slices, chopped parsley, chopped scallions, salt and pepper. Place the baking dish in the oven and bake until the fish is just cooked through and lightly golden on top, 25 to 30 minutes. While the fish is cooking, make the pan sauce by melting 1 1/2 tablespoons of butter in a medium saucepan over medium-high heat. Add the shrimp shells and cook, stirring frequently, until the shells are lightly golden, toasted and fragrant, 4 to 6 minutes. Add the shallots and remaining 1 teaspoon of garlic and cook, stirring, for 1 minute. Add the white wine and cook until evaporated, 1 minute. Add the water or broth, heavy cream , remaining 1 teaspoon of Essence, Worcestershire sauce , bay leaf and hot sauce and reduce the heat to medium-low. Cook, stirring occasionally and using the spoon to mash the shells into the sauce, until the liquid is reduced enough to coat the back of a spoon, about 8 minutes. Strain the sauce through a fine-mesh sieve , pressing on the shells to release as much liquid as possible, and then return the sauce to the saucepan. Add the remaining 1 tablespoon of green onions and keep warm until ready to serve the fish . When the fish is done, remove it from the oven and divide each fish into portions and transfer to serving plates. Remove the sauce from the heat and whisk the remaining butter into the warm sauce. Serve the warm sauce ladled over the fish. Pass the lemon wedges at the table.
