Remove any fat and gristle from the roast and cut into strips 1/2 inch thick by 2 inches long. Season with 1/2 teaspoon of both salt and pepper.
In a dutch oven over medium heat, melt the butter and brown the beef strips quickly, then push the beef strips off to one side. Add the onions & mushrooms and cook slowly for 3 to 5 minutes, then toss together with the beef strips.
Sprinkle the flour over the beef/mushroom/onion mixture. Mix together quickly, stirring to brown flour. Pour in Worcestershire, beef broth and merlot, stirring to combine. Bring to a boil, stirring constantly. Add noodles, lower the heat, cover and simmer for 1 hour or until the meat is tender.
Five minutes before serving, stir in the sour cream. Heat briefly then salt and pepper to taste.