In a medium bowl, combine the baking soda and the steak. Make sure that the steak is well coated in the baking soda. Place beef in the refrigerator for 15 minutes. Thoroughly rinse the beef in cold water and pat dry. Make sure the beef is dry before placing in the marinade.
In a medium sized bowl, combine all ingredients for the marinade. Add the steak and stir to combine. Make sure that the steak is well coated in the marinade. Set aside. Allow the steak to marinate for at least 15 minutes.
In a small bowl, combine all of the ingredients for the seasoning. Set aside.
Meanwhile, break the noodles apart and place into a large bowl. Try to break the noodles into individual noodles if possible.
Add the spinach, and rice noodles and stir to combine. Add seasoning to the noodle mix and stir to combine. Cook until the noodles are slightly charred, about 2 minutes.
Serve hot.
Recipe by The Little Chef at http://littlechefblog.com/beef-chow-fun/