Cook egg noodles per package directions, until al dente. (I took a tip from Gimme Some Oven and added my noodles to the boiling water about the time the beef stock mixture was added to the skillet)

Meanwhile, melt the butter in a large skillet over medium-high heat. Add the steak in a single layer, seasoned with salt and pepper, and let it cook for about 3 minutes to get a good sear. Turn the steak, and cook on the other side until browned, about another 3 minutes. Then remove steak from skillet with a slotted spoon, and transfer to a separate plate. Set aside for later. Be sure not to overcrowd your skillet. If you need to, cook your steak in 2 batches.

Add the remaining 2 Tbsp. butter. Add the onions and saute about 3 minutes. Add garlic and mushrooms, and stir. Continue sauteing for an additional 5-7 minutes, or until the mushrooms are browned and the onions are soft and translucent. Add the white wine, and deglaze the pan by using your wooden spoon to scrape the brown bits off the bottom of the pan. Let the mixture cook for an additional 3 minutes.

In a separate bowl, whisk together the beef stock, worcestershire sauce and flour. Pour the beef stock mixture into the pan, and stir to combine. **drop your egg noodles in the boiling water to cook**

Let the beef stock mixture simmer for 5 minutes, stirring occasionally. Then stir in the sour cream and mustard until combined, and then slide the cooked steak back in. Season with additional salt and pepper if needed.

Toss egg noodles with butter, minced parsley and sliced green onions. Ladle beef stroganoff over the top of the noodles and sprinkle with additional parsley and green onions.