This Steak Dinner for Two features filet mignon steaks (also known as beef tenderloin steaks) because of their versatility and ease of cooking. Feel free to substitute your favorite cut of steak - we sometimes substitute a good rib eye.
Preheat the oven to 425 degrees F.
Heat a bit of olive oil in your favorite cast iron skillet over medium high heat.
When the oil shimmers in skillet, add the seasoned beef filets, browning then on both sides. Transfer the skillet to the center rack of the preheated oven; roast the filets until they reach 135 degrees F. at the center, for medium-rare doneness, approx. 8-10 minutes.
Transfer the filets to a plate; tent well with foil to keep warm. (At this point, they will raise 5-10 more degrees in internal temperature to 140-145 degrees, medium rare.)
Return the hot skillet to the burner over medium high heat. Add the thyme to the pan drippings in the skillet, cooking and stirring for a few seconds, then add the wine. In a small bowl, whisk the cornstarch into the broth, then add this mixture to the skillet. Let the sauce simmer until thickened and slightly reduced.
Serve the steaks drizzled with the prepared warm sauce and cooked tarragon mushrooms.
Heat a good swish of olive oil in a cast iron skillet over medium-high heat. Add the scallion whites along with the mushrooms to the skillet.
Cook the mushrooms, stirring occasionally until they are nicely softened and the juices evaporate, 6 to 8 minutes. Stir in scallion greens and tarragon; remove from heat. Lastly, season to taste with salt and pepper.