I too love hibachi or grilled Zucchini. I have many ways that I use to grill them in combination with other veggies and/or meat, but perhaps the most simple is as a kabob over hot coals.
I cut one to 1.5 inch squares of the Zucchini and push it onto the skewer so that there is an empty spot between each piece of equal size.
Then, about 4 inches from the coals, I allow the Zucchini to just start showing some browning and turn it 90 degrees, (one quarter of a full turn).
You must be right there to watch. This isn't a walk away type of cooking.
As soon as the second side is slightly browned, I baste it lightly with soy sauce, but not enough to drip into the fire. One or two drops per/piece is enough.
When all four sides have been slightly browned, remove it from the fire and serve immediately. I've seen a professional cook 20 of these at once, all being turned perfectly and on time. That's pretty busy. For two people, four of them, served with other parts of the meal that are slow cooked perhaps, makes this a wonderful addition to a meal.
Don't season with anything else. The natural flavor of the Zucchini with a tiny bit of soy flavor will be enough.
Sometimes, it takes doing this two or three times before becoming very good at it. All will be good to eat, but with practice, it gets better and better!
A note about the size of the pieces; in countries where chop sticks are used to eat meals, it's considered rude to serve pieces that are too large for the mouth of the eater or too large to be handled easily with the chop sticks. A wise chef literally notes the size of each persons mouth, (kids of course have much smaller mouths), and make each portion appropriate for that person to eat comfortably. Too small and it's also an implied insult. Each bite should be a nice full mouth of food that can be chewed comfortably without the mouth having to open and expose the chewed food to supper companions. This is all an important part of Asian cooking.
Good luck to you!
