In a mixing bowl, combine mirin, minced garlic, grated ginger, and sesame oil to create a flavorful marinade. Add cubed sirloin steak, cover, and refrigerate for at least 30 minutes.

While the steak marinates, wash and slice your vegetables: cut carrots and zucchini into thin rounds, and quarter the mushrooms.

Heat a tablespoon of oil in a large skillet over medium heat. Once shimmering, add the sliced carrots, zucchini, and mushrooms. Sauté for 5–7 minutes until tender.

Increase heat to medium-high and add the marinated steak to the skillet. Cook for about 4–5 minutes until browned and done to your liking.

Remove the skillet from heat. Mix steak and vegetables thoroughly and serve over warm fried rice, drizzling soy sauce to taste.