Slice mushrooms into ¼ wide slices. Set aside.
Pound steak out with meat mallet (or rolling pin) and flatten them out to about ½ inch thick. Slice steak against the grain in to thin ¼ slices. discarding excess fat and set aside.
Dice onion into ¼ piece and set aside.
Cook egg noodles according to package directions for al dente. Drain well then cover and set aside.
Meanwhile, pre-heat skillet on medium-high. Add butter and let melt. Add in steak and cook until completely brown, 2-3 minutes on each side. Remove steak from skillet an cover then set aside.
Leave pan dripping from steak in skillet. Add olive oil and heat. Add garlic and saute for 30 seconds. Add mushrooms and onions saute for 7 minutes, or until tender.
Pour in beef broth, Worcestershire sauce, thyme, salt, ground black pepper and flour. Mix well until completely incorporated. Add steak back in to reheat and Simmer until thickened, 3-4 minutes.
Lower heat to low Add sour cream and Dijon must and mix well. Cook 1-2 to melt sour cream.
Add cooked egg noodles to sauce, mix the noodles into the sauce until the are completely covered.
Serve will hot, sprinkle chopped parsley and salt and pepper to taste.