Add egg noodles to boiling water and cook till al dente; drain. Meanwhile, heat butter in a large skillet over medium-high heat. Add steak pieces and cook for 3-4 minutes. Remove meat from pan when the centers are still pink; cover and set aside.
Add onion, garlic and mushrooms and reduce heat to medium. Cook until veggies are soft and fragrant, 3-4 minutes. Add the flour and whisk until mixed together. Add beef broth, Worcestershire, salt, pepper and sour cream. Simmer until mixture is thick, about 5 minutes (simmer longer, if needed).
Add the steak back to the pan and cook until completely heated through. Serve immediately over cooked noodles and top with sliced green onions (if desired).
Notes
For a gluten free meal, serve over rice and replace the flour with cornstarch. Also keep an eye on the labels for the broth and Worcestershire sauce.
Add 1 tablespoon of dijon mustard along with the beef broth mixture for an extra splash of flavor.
Throw the leftovers (if there are any!) into a mushroom soup the following day.
Mushrooms and beef stroganoff are made for each other. Add a can of cream of mushroom soup to the sauce mixture or add extra mushrooms to the recipe.
Add extra garlic for a spicier meal or add a few splashes of your favorite hot sauce toward the end of cooking the meal. A pinch of cayenne pepper would be a great spicy addition, too.