Sprinkle both sides of meat with salt, pepper, and 1 tsp. Dill. Place in slow-cooking pot. Add water and vinegar. Cover and cook on low for 7 to 9 hours or until tender. Remove meat from pot. Turn control to high. Dissolve flour in small amount of cold water; stir into meat drippings. Stir in additional 1 tsp. Dill. Cook on high about 10 minutes or until slightly thick. Stir in sour cream; turn off heat. Slice meat; serve with sauce.