Dredge the turtle in flour. In a large, heavy-bottomed saucepot over high heat, melt the butter and brown the turtle pieces, about 10 to 12 minutes. Remove the turtle from pan and allow to cool enough to handle. Deglaze the pan with red wine, scraping the bits from the bottom and sides.
Add the celery, onion, carrots to the pot. Stir in the beef stock, 1/2 cup water, and Worcestershire and continue to cook over medium-high heat. In small bowl whisk together the cornstarch, paprika, allspice, parsley, nutmeg, ginger, tomato paste, salt and pepper and 2 tablespoons water. Add to the vegetable mixture.
Once the turtle has cooled, put meat in cheesecloth, and tie closed with butcher's twine and add to the pot. The turtle needs to be in cheesecloth so that it can be extracted from the stew before pureeing. Continue to cook over medium-high heat until the mixture boils, then reduce the heat to low and simmer for 2 hours. After 2 hours, remove the turtle in the cheesecloth and strain vegetables from stock. Transfer cooked vegetables to a food processor and process until a chunky paste is achieved. Remove the turtle from cheesecloth and return the meat to saucepan with reserved liquid and pureed vegetables. Cook over medium heat until desired thickness is achieved, about 20 minutes. Ladle into serving bowls and finish with a little sherry in each bowl before serving.