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 350 degree F oven and cook for 20 minutes or until brown on top.