Pat the steak dry, season with salt and pepper, and heat vegetable oil in a skillet. Sear the steak for 2-3 minutes on each side until browned. Let it rest.

In the same skillet, add more oil and sesame oil, then sauté mushrooms and onion for 4-5 minutes. Add zucchini and cook for 2-3 more minutes.

Slide vegetables to the side, melt butter in the cleared area, then add minced garlic and sauté for 30 seconds.

Whisk together soy sauce, mirin, and honey in a bowl, then pour it into the skillet with vegetables. Let it simmer to meld flavors.

Slice the rested steak, add it to the skillet, and stir to coat in sauce. Simmer for another 1-2 minutes until heated through.

Transfer to a serving platter, garnish with sesame seeds and green onions, and serve hot.