Cut beef into smaller chunks if needed, and pat dry. Put the meat on a plate or in a mixing bowl.
In a small bowl mix salt, pepper and nutmeg. Sprinkle evenly over the beef and toss well to distribute. After the meat is seasoned, sprinkle with the flour. Toss to coat all the beef with flour.
Melt the butter and brown the meat in batches. Add the browned beef to the slow cooker. Add the rest of the ingredients EXCEPT the sour cream. Stir to combine and cook covered for 5 or 6 hours on low.
A few minutes before serving stir in the sour cream. Taste for seasoning, correcting if necessary. Serve over egg noodles.