In a medium mixing bowl, combine all Salisbury steak ingredients, except butter. Mix well. Form beef mixture into small balls.
Drain any excess grease, if needed.
Add onion and garlic. Sauté, stirring occasionally, for 3-4 minutes scraping pan drippings.
Stir in sliced mushrooms and continue cooking for further 2 minutes.
Sprinkle all-purpose flour over mushrooms and onions. Stir well and cook for another 2 minutes.
Pour in beef broth, Worcestershire sauce, then season with salt and black pepper. Cook, stirring for a few minutes, then return meatballs back into the pan. Mix well.
Cover pan and cook for about 30 minutes, stirring occasionally. The gravy will also thicken up as it cools. Open the lid and stir in combined cornstarch and water, continue cooking, stirring continuously.
Once noodles are cooked and meatballs are tender, mix together and enjoy!