In a mixing bowl, combine mirin, minced garlic, grated ginger, and sesame oil. Add cubed sirloin steak, ensuring it is evenly coated with the marinade. Cover and refrigerate for at least 30 minutes.

While the steak marinates, wash and chop your vegetables. Slice the carrots and zucchini into thin rounds, and quarter the mushrooms. Set aside.

Heat a large skillet over medium heat and add a drizzle of oil. Once shimmering, add the prepared vegetables. Sauté for 5 to 7 minutes until tender.

Increase the heat to medium-high and add the marinated steak to the skillet. Sear for 4 to 5 minutes until cooked to your desired doneness.

Mix the cooked steak with the sautéed vegetables in the skillet. Serve over fried rice and drizzle with soy sauce.