Cut the beef into thin pieces ¼ inch thick
Put the beef and flour in a large zip lock bag and shake until the beef is coated.
Melt the butter in a skillet over medium heat
Add the onions and sauté about 2 minutes
Add the onions and continue for another 4 minutes
add the garlic and cook for another minute
Remove the onion, mushroom, and garlic to a bowl
Add the oil to the skillet and cook the beef in batches until a crust forms on the outside - don't overcook!
There should be flour left in the bag. Save it for a later step.
When all the beef is ready put all of the beef and the onion mixture in the skillet with 1 cup of the broth. Bring to a boil and then reduce to a simmer and cover. Simmer for 15 minutes
Raise the heat again until the liquid starts to boil, Whisk the remaining flour into the last ½ cup of broth and add it to the skillet. stirring until the sauce in the skillet is thick and consistent.
Remove from the heat and cover
Cook the egg noodles according to package directions. When finished, drain.
Stir the sour cream into the sauce until smooth throughout.
Serve over the noodles