In a large heavy skillet cook the onion and the bell peppers in the butter over moderately low heat, stirring, until they are softened. Add the flour, and cook the roux mixture, stirring, for 3 minutes. Add the broth, the sherry, and the half-and-half, whisking. Bring the mixture to a boil, whisking, and stir in the turkey, the potato, the Worcestershire sauce, the lemon juice, the hot pepper sauce and salt and black pepper, to taste. Simmer the mixture, stirring occasionally, for 10 minutes, thinning the mixture with water if necessary. The hash may be prepared up to this point 2 days in advance and kept covered and chilled. Reheat the hash, thinning the mixture with water if necessary. Stir in the parsley and transfer the hash to a chafing dish.