01 - Pat steak cubes dry using paper towels. Toss with 1 tablespoon olive oil, kosher salt, and black pepper. Set aside.
02 - Heat a large skillet over medium-high heat. Add 1 tablespoon olive oil and mushrooms. Season with salt and sauté for 4-5 minutes until golden and tender, stirring occasionally. Transfer mushrooms to a plate.
03 - In the same skillet, add half the steak cubes in a single layer. Sear undisturbed for 2 minutes, then flip and cook 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. When melted, add garlic and thyme, cooking for 30 seconds until fragrant.
05 - Return steak bites and mushrooms to skillet. Toss to coat evenly in garlic butter for 1 minute. Drizzle lemon juice over and sprinkle with parsley.
06 - Serve immediately, garnished with additional parsley if desired.