Cut steak into thin strips, chop onions, and rinse and dry mushrooms
Melt butter in a large sauce pan, add meat. Cook until browned. After 3-4 minutes add onions, mushrooms, salt, pepper, and garlic. Complete cooking until all meat is cooked through.
Turn heat to low. Add sour cream. Reduced fat sour cream is okay, I would not recommend using low fat. Stir and cook only to warm.
Serve over egg noddles. I like this with wide egg noodles, but we made double portion of the thin variety with yesterday's dinner. Saved me time today. I just popped them back into the strainer and ran hot water over them to serve.