1. In a large pot brown the sirloin in the extra virgin olive oil. Once browned, remove the sirloin and add the onions. Cook until lightly browned then add the butter and flour. Cook the flour in the butter for about 2 minutes then add the beef broth and the sirloin back into the pot. Season with salt and pepper to taste.
2. Let the beef broth simmer for 10 minutes until the sauce thickens.
2a. Meanwhile in another large pot boil water and cook the egg noodle to desired doneness. Drain.
3. Add the sour cream to the pot with the beef and lower the heat way down. Heat for about 3 minutes - do not let this pot come to a boil.
4. Serve beef over a bed of noodles.