Poke the steak strips liberally with a fork and toss in a baking dish. Pour the soy sauce on top and flip the steaks to coat. Let sit in the fridge for at least 15 minutes, covered.
When ready to cook, place the mushrooms in a large bowl, cover, and microwave 4 to 5 minutes. Drain the liquid and set aside.
Combine the dry mustard, water, and sugar in a small bowl and whisk until a paste forms. Season with salt and pepper.
Heat the oil in a large non-stick skillet over medium heat and pat the steak strips dry. Place the steaks in the skillet and brown on all sides, 6 to 9 minutes. Remove meat from skillet and transfer to a bowl. Cover and set aside.
Add the mushrooms and onion to the skillet. Season with ½ teas salt and cook 6 to 8 minutes, until veggies begin to brown.
Add the flour and tomato paste. Stir and cook for 1 minutes.
Whisk in the beef broth and ⅓ cup wine, scraping the bottom of the pan to remove any browned bits. Add the mustard paste and bring mixture to a simmer.
Lower heat to medium and cook until sauce thickens, 4 to 6 minutes.
Cut the steak into bite sized pieces across the grain. Return the steak and any juices to the bowl. Stir to coat.
Remove the skillet from heat and stir in the sour cream, remaining wine, and chives.
Season with salt and pepper to taste and server over egg noodles.