"An easy way to make a delicious restaurant quality filet mignon steak with just a few simple make-ahead ingredients. No grill required! The butter can made several days ahead with the excess kept for future recipes."
Mix the butter, chives, tarragon, and garlic together in a bowl until well-blended. Place the butter mixture on a large piece of plastic wrap. Wrap the butter with the plastic and shape it into a log about 1-inch thick. Place the log in the refrigerator to chill.
Season the beef tenderloin steaks with salt and black pepper. Place the dried mushrooms in a spice grinder or food processor. Process until the mushrooms are finely ground. Spread some of the ground mushroom on a plate. Press each steak into the mushroom powder until well coated, adding more mushroom to the plate as necessary.
Melt about 2 tablespoons herb butter in a large skillet over medium heat. Arrange the steaks in the skillet and cook until they start to firm, and are reddish-pink and juicy in the center, about 6 minutes per side. An instant-read thermometer inserted into the center should read 130 degrees F (54 degrees C) for medium rare, 140 degrees F (60 degrees C) for medium. Top each steak with 1 teaspoon herb butter before serving.