In a medium-sized bowl, whisk together the soy sauce, red wine vinegar, maple syrup, Worcestershire sauce, and garlic powder until combined.
Place a gallon-sized ziplock bag in a large bowl. Place the steaks in the bag, and pour in the marinade. Press out as much air as possible and seal it, then place the bowl with the bag in the refrigerator. Allow the steak to marinade for a minimum of 1 hour, or up to overnight.
Heat 1 tablespoon of the olive oil in a large saucepan over medium-high heat. Add the mushrooms and salt and sauté until the mushrooms release their juices, about 8 to 10 minutes, stirring every 2 or 3 minutes. Add the fresh thyme leaves and black pepper, reduce heat to medium low, and continue cooking until the mushrooms have deepened in color, shrunk slightly, and are pleasantly fragrant, about 10 to 15 minutes more, stirring every 3 minutes or so.
Preheat the oven to 400 degrees Fahrenheit. Pat the steak dry. Heat the remaining 2 teaspoons of olive oil in a large skillet pan over medium high heat. Add the steaks and sear them on both sides (about 4 min each side). Then transfer the skillet to the oven and cook until desired doneness.
For reference, the interior temperature of a steak for the range of “doneness” is: 125°F is rare, 135°F is medium rare, 145°F is medium, 150°F is medium well, and 160°F is well-done. The USDA recommends steaks and roasts be cooked to 145°F (medium) and then rested for at least 3 minutes.