Using a paper towel, pat dry your steaks until the are as dry as possible all over [this will ensure you get a better crust on your steak]. Generously season both sides of the steaks with kosher salt and cracked black pepper.
Heat a cast iron skillet over medium high heat for 4 minutes without touching. When hot, add the oil to the skillet. When the oil just begins to smoke, you are ready to cook your steaks. You want to be sure the skillet is super hot.
Carefully place your filets into the skillet and cook until golden browned on both sides and cooked to your liking, this will depend on the size of your steaks and how you like yours cooked. My filets were on the smaller side, and I cooked mine for 2-3 minutes on each side for medium/medium-rare cook.
Transfer cooked steaks to a plate and let rest while you make the mushroom sauce.
For the Sauce:
Add the onion and garlic and cook, stirring, until the onions are slightly tender, about 2 minutes.
Add the mushrooms with a pinch of salt and pepper and continue to cook, stirring, to brown the mushrooms a bit, about 3 minutes. As the mushrooms begin to become tender, add the thyme, beef broth and balsamic and stir to combine.
Continue to cook, stirring, until the sauce reduces by about half, 3 to 4 minutes.
Once reduced, spoon sauce onto your filets. Serve and enjoy!
Serve with my Hasselback Potatoes and a simple arugula salad with olive oil and lemon.