Marinate the Steak:
In a small bowl, combine the soy sauce, mirin (or honey), minced garlic, ginger, sesame oil, and red pepper flakes.
Place the steaks in a shallow dish or Ziploc bag, pour the marinade over the steaks, and let them marinate for at least 30 minutes (or up to 2 hours).
Prep the Grill:
If using a Blackstone griddle or regular grill, preheat it to medium-high heat.
Lightly oil the griddle or grill grates with olive oil to prevent sticking.
Cook the Steak:
Once the grill is hot, remove the steaks from the marinade and season both sides with salt and black pepper.
Place the steaks on the hot griddle or grill, cooking for 2-3 minutes per side for medium-rare (or longer depending on your desired doneness).
While the steaks are cooking, melt the butter in a small pan with crushed garlic for extra flavor.
Rest the Steak:
Remove the steak from the grill and let it rest for 5 minutes. This allows the juices to redistribute.
Grill the Vegetables (Optional):
If making hibachi-style vegetables, add the sliced zucchini, onion, mushrooms, and broccoli to the griddle. Drizzle with a little soy sauce and cook for 5-6 minutes until they are tender and slightly caramelized.
Serve:
Slice the rested steak against the grain and serve it with your choice of grilled vegetables. Garnish with green onions and a squeeze of lemon or lime for extra freshness.