In a mixing bowl, combine mirin, minced garlic, grated ginger, and sesame oil. Stir well to create a marinade. Place the sirloin steak in the mixture and let marinate in the refrigerator for about 30 minutes.

While the steak marinates, prepare the fried rice according to package instructions or your favorite recipe. Use a large skillet over medium heat and add oil to prevent sticking. Cook until heated through and slightly toasted.

Heat a large skillet or wok over medium-high heat, add oil, and sauté the sliced carrots, zucchini, and mushrooms for 5-7 minutes until tender.

Increase the heat to high and add the marinated sirloin steak, searing for 5-8 minutes, flipping halfway until caramelized.

Remove the steak from the skillet, let rest for a few minutes before slicing. To serve, spoon fried rice into bowls, layer with sautéed vegetables, and top with steak slices.