Preheat the oven to 325º F. Roll meat lightly in flour. Slice onion thinly. Melt butter in Dutch oven. Add onion and cook until softened.
Add beef, and lightly brown. Remove beef from pot Turn the heat to high and add the wine. Scraping up the brown bits, cook until wine reduces slightly. Add the beef back into the pot.
Then add beef stock and mushrooms. Season with salt and pepper. Place in the oven for 2-2 ½ hours, stirring once. Add additional broth if needed.
During the final 30 minutes, bring a salted pot of water to a boil. Cook pasta until al dente. Remove pot from the oven, stir in sour cream, and sprinkle with fresh parsley.