01 - Pat steak cubes dry with paper towels. Toss with 1 tablespoon olive oil, kosher salt, and freshly ground 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 to 5 minutes, stirring occasionally, until golden and tender. Transfer mushrooms to a plate.
03 - In the same skillet, add half of the steak cubes in a single layer. Sear undisturbed for 2 minutes, flip and cook an additional 1 to 2 minutes until browned but medium-rare. Remove to a plate and repeat with remaining steak cubes.
04 - Reduce heat to medium. Add butter to the skillet; once melted, add minced garlic and 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 one minute. Drizzle with lemon juice and sprinkle with fresh parsley.
06 - Serve immediately, garnished with additional parsley if desired.