PREPARING THE TEPPANYAKI SAUCE
In a small saucepan, heat the sake and mirin on medium heat. Let that come to a boil for 30 seconds. Then, add the brown sugar, soy sauce, minced garlic, and grated ginger. Let that cook on medium heat for 2 minutes. Then, whisk in the sesame oil and toasted white sesame seeds. In a small cup or bowl, mix together the water and cornstarch to make a slurry. Whisk the slurry into the soy sauce mixture in the saucepan.

Let the sauce come to a boil and thicken, while whisking. Then, turn off the heat.Let the sauce cool. Once cooled, transfer the sauce to a glass jar, and refrigerate for up to 3 days. NOTE: The sauce will have better flavor if you let it sit in the refrigerator overnight.

PREPARING THE ONIONS, ZUCCHINI, AND MUSHROOMS
Cut the Miyazakigyu Wagyu flanken-cut boneless short ribs in half, widthwise, and let them come to room temperature for 1 hour before cooking. In addition, pull the teppanyaki sauce from the refrigerator, and allow it to sit at room temperature. Heat the griddle/pan on medium-high heat, and use 2 tablespoons of grapeseed oil to coat the griddle/pan. Once the pan is hot, add the onion rings. Cook the onions until they start to caramelize.

Pour 1/4 cup of sake over the onions, and continue cooking until the onions are softened. Using a spatula move them to the side of the griddle, and start cooking the zucchini sticks and quartered mushrooms. Once the zucchini and mushrooms are caramelized, pour the other 1/4 cup of sake over the zucchini and mushrooms. Cook, while stirring up the ingredients, until the sake dissolves and everything is cooked to your liking. Move the onions, zucchini, and mushrooms to a platter, and tent with foil

PREPARING THE MIYAZAKIGYU WAGYU SHORT RIBS
Wipe down the griddle, and heat on medium-high heat. Use another 2 tablespoons of grapeseed oil on the pan, and heat until hot. Season the Miyazakigyu Wagyu short ribs with kosher salt. On the hot griddle, sear off the Miyazakigyu Wagyu short ribs for 30 seconds on each side. This should get you nice cara-melization without overcooking the beef.

FINAL STEPS
Place the teppanyaki Miyazakigyu Wagyu short ribs on the platter with the onions, zucchini, and mushrooms.Serve hot with a bowl of teppanyaki sauce for dipping.Enjoy!