Preheat the oven to 400ºF.
Put the potatoes in a large saucepan and add enough water to cover. Add the salt and bring to a boil. Reduce the heat to medium and simmer, covered, until they are fork tender, about 10 minutes. Drain. Return the potatoes to the pan over high heat and let sit for several minutes to dry completely. Push the potatoes through a food mill or potato ricer. Let cool.
Heat the olive oil in a medium-size sauté pan over medium heat. Add the tasso and cook, stirring often, for 2 to 3 minutes. Add the green onions, tomatoes, shallots, and garlic. Season with Essence. Cook, stirring, for 1 minute. Add the heavy cream, Worcestershire, and hot sauce. 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. Set aside and keep warm.
Put the potatoes in a large mixing bowl and stir in 2 tablespoons of the butter, the flour, and egg yolks. Blend until the mixture is smooth. Season with salt and pepper.
Flour your hands and your work surface and keep them dusted throughout the rolling and cutting process. Form the mixture into a ball. Place the ball on the floured surface. Divide the dough evenly into 2 balls and roll each into a log about 1 inch thick and 20 inches long. Cut the logs crosswise into 1/2-inch-thick slices. With your index finger, press each piece of dough against the tines of a fork to form a decorative design.
In a large saucepan, bring the salted water to a gentle boil. Drop in the gnocchi several at a time and cook for 5 minutes. The gnocchi are done when they float to the surface and cook for another 2 minutes. Remove the gnocchi from the water with a slotted spoon and drain completely. Season with salt and pepper.
Lightly grease a large rectangular baking dish with the remaining 2 tablespoons butter. Lay the gnocchi on the bottom of the pan. Pour the sauce over the gnocchi and sprinkle with the cheese. Bake until the top is golden brown, 8 to 10 minutes. Before serving, garnish with the chives.
Yield: 6 servings