01 - Pat steak cubes dry with paper towels. Toss with 1 tbsp olive oil, kosher salt, and black pepper. Set aside.
02 - Heat 1 tbsp olive oil in a large skillet over medium-high heat. Add mushrooms, season with salt, and sauté for 4-5 minutes until golden and tender. Transfer mushrooms to a plate.
03 - Add half of the steak cubes to the skillet in a single layer. Sear undisturbed for 2 minutes, flip, and cook for 1-2 minutes until browned and medium-rare. Remove to a plate. Repeat with remaining steak cubes.
04 - Reduce heat to medium. Add butter to the skillet and allow it to melt. Stir in minced garlic and dried thyme; cook for 30 seconds until fragrant.
05 - Return steak bites and mushrooms to the skillet. Toss to coat evenly in the garlic butter for 1 minute. Drizzle lemon juice over and sprinkle with chopped parsley.
06 - Plate immediately, garnishing with additional parsley if desired.