Heat the butter in a 12-to-14-inch sauté pan until melted and foaming. Add the onion, celery, salt, pepper, thyme, and bay leaf. Stir well to coat the vegetables, and cook over medium heat for 5 minutes, stirring often, until the vegetables are wilted and somewhat tender but not colored. Sprinkle the flour over, and stir well. Cook for minute, stirring constantly, then, off heat, slowly stir in the chicken stock (or other liquid), followed by the half-and-half. Return the pan to the heat, and bring to a gentle simmer. Simmer for 1 minute, and taste for seasoning; you will most likely need more salt, unless you added gravy or stock that was highly seasoned. Add the turkey and chestnuts, and simmer until heated through. Taste again for seasoning. Add the optional booze, and cook 1 minute longer to cook off the alcohol.

Serve hot, spooned over toast or thin cornbread.