In a mixing bowl, combine the potatoes, 1 egg and the spinach mixture. Season with salt and pepper. Mix well. Stir in 1/2 cup of the bread crumbs. Divide the mixture in fourths and form into round cakes, about 1-inch thick. Season the flour with Essence. Whisk the remaining egg and milk, together. Season the remaining 1 cup bread crumbs with Essence.
Dredge the cakes in the flour. Dip each cake in the egg wash, letting the excess drip off. Dredge the cakes in the bread crumbs, coating completely. In another saute pan, heat the oil. When the oil is hot, add the cakes and pan-fry until golden brown, about 2 to 3 minutes on each side. Remove from the oil and drain on paper towels. Season with Essence. Set aside and keep warm. Drain the oysters, reserving the liquor. Set aside. In another saute pan, melt the butter. Add the onions. Season with salt and pepper. Saute for 2 minutes. Add the garlic and continue to saute for 1 minute. Add the reserved oyster liquor, cream, lemon juice, and Worcestershire sauce. Season with the hot sauce, salt and pepper. Bring the mixture to boil and then reduce the heat to medium and simmer until the cream thickens, about 4 minutes. Season the oysters with salt and pepper. Stir in the oysters and cook for about 2 minutes or until the edges curl. Add the parsley and remove from the heat.