To a large cast iron skillet over high heat, heat 2 tablespoons of oil until just starting to smoke. Add the steaks and garlic and cook for about two minutes on each side, until the steaks register 115°F (for medium-rare) on a digital thermometer. Remove steaks and set aside.

To the same pan, add the remaining oil and bring to temperature. Add the mushrooms and sauté until soft, 2 to 3 minutes. Remove from pan and set aside with the steaks.

To the same pan, add the broth, butter, lemon juice, and red pepper flakes. Lower heat and simmer the sauce until it thickens slightly. Add the mushrooms and steak back to the pan and toss to cover with sauce. Garnish with parsley to serve.