# Steps:
01 - Combine steak cubes with soy sauce, mirin, sesame oil, minced garlic, and black pepper in a bowl. Let marinate for at least 10 minutes while preparing remaining ingredients.
02 - Heat 1 tablespoon vegetable oil in a large skillet or wok over medium-high heat. Add marinated steak and cook for 2–3 minutes, stirring occasionally, until browned but still tender. Remove steak from pan and set aside.
03 - Add remaining 1 tablespoon oil to the same pan. Sauté onion, carrots, zucchini, and mushrooms for 4–5 minutes until just tender.
04 - Push vegetables to the side of the pan. Pour beaten eggs into the cleared space and scramble until just cooked.
05 - Add rice, peas, and cooked steak to the pan. Drizzle with soy sauce and toss everything together, breaking up any clumps of rice.
06 - Stir in butter and half the green onions. Cook for another 2–3 minutes, stirring frequently, until heated through and slightly crispy. Taste and adjust seasoning with salt and pepper as needed.
07 - Serve immediately, garnished with sesame seeds and extra green onions if desired.
