Boil your egg noodles in a small to medium sized stock pot until they are fully cooked through and drain them.
While your noodles are boiling, get your butter melting in your sauce pan.
Dice onion and put into the skillet with butter. Sauté the onions on medium heat until they begin to turn translucent.
Cut up your tenderized cube steak into 1/2 to 3/4 inch pieces.
Put the meat in the skillet.
Salt and pepper your meat in the skillet and cook the beef on medium heat until the meat is cooked through. If you want to speed up the process, cover the skillet with a lid.
Once the meat has finished cooking, do not drain any of your grease.
Stir the cans of cream of mushroom soup into your beef mixture and bring it to a boil.
Pour your piping hot beef mixture into your hot noodles and stir to coat them thoroughly.
Add the sour cream to the mixture and stir until fully combined.
Salt and pepper to taste.
Serve warm and enjoy!