Pat dry chicken. Put flour, salt, pepper, and other seasoning in zip type bag. Add chicken pieces, coat with flour mix, and shake off excess flour mix. Brown chicken in butter/oil. Arrange chicken in baking dish, 1 layer.
In pan in which chicken was browned, make a sauce by reducing fat to 2 Tbsp. Add mushrooms and saute slightly. Add more butter if needed. Add sour cream, wine, and rosemary. Simmer, deglazing pan. Pour over chicken.