Brown chicken in butter with the chopped onions. Pour heated vodka over the chicken & onions. Add the garlic, salt, pepper, & parsley. Remove chicken from the pan, dredge in the flour, add the tomato paste, & chicken broth to the pan. Stir-in the sourcream & feta cheese. Bring to a boil, stirring constantly. Add the chicken again to the mixture, reduce heat and simmer for 20-30 minutes. Arrange the chicken in a deep casserole dish. NOTE*** At this point this dish may be frozen or refrigerated for later cooking to finish. Pour the mixture over the chicken and cook in preheated 180ºC oven and cook for 20 minutes or until brown on top.