Thinly slice the steak, mushrooms and onions. Mince the garlic. Heat a cast iron skillet on high heat until smoking, add olive oil and sear the steak for 3 min per side. Work in batches so you don't overcrowd the pan. Set seared meat aside. Turn the heat down to medium. Add butter and a splash of beef broth to the pan, add the mushrooms and onions and sauté for 8 minutes. using a flat bottomed wooden spatula to scrape the brown bits from the bottom of the pan. Add the garlic and sauté for one minute. Add the flour and stir well, cook for 2 min. Add in cream and stir. Place the sour cream into a small bowl and add 2 tbsp of the sauce to the bowl and stir to temper the sour cream. Add the tempered sour cream to pan. Add the meat and juices, stir and cook for 5 min. Add in parm cheese, stir, add in the chives, stir again and turn off heat.

Boil a salted pot of water. Drop in thinly sliced strips of zucchini and yellow squash. Cook for 5 minutes. Drain well. Use a couple of paper towels to soak up remaining water.

Divide the zoodles among the plates and top with stroganoff. Finish with a dollop of sour cream.