Heat 2 tablespoons of the olive oil in a large sauté pan over medium heat. Add the tasso and cook, stirring often, for 2 to 3 minutes. Add the yellow onions and season with Essence. Add the crawfish and cook all, stirring, for 2 minutes. Add the tomatoes and garlic, season with salt and pepper, and cook, for 3 minutes more. Add the heavy cream, Worcestershire, and hot sauce and bring to a boil, then reduce the heat to medium and simmer, stirring occasionally, until the cream thickens and reduces by one third, 6 to 8 minutes. Add the green onions. Season again with salt and pepper. Set aside and keep warm.

Season the grouper with Essence. Heat the remaining 1/4 cup olive oil in a large sauté pan over medium-high heat, then add the fish and sear until the fillets are lightly golden and flake easily with a fork, 5 to 6 minutes on each side. Remove and drain on paper towels.

To serve, lay a fillet on each of the plates and divide the crawfish cream equally among the four plates.