A glut of summertime zucchini brings the inevitable scramble to find new ways to use the notoriously prolific vegetable. Fortunately, the green summer squash doesn't have to take the night off when it's barbecue time. Properly prepped and cooked zucchini comes off the grill nicely charred, with its nutty sweetness kicked up a notch. The vegetable cooks quickly on barbecue grates, but just how quickly depends on how you've sliced it.
Zucchini rounds are easiest to maneuver if you put them on skewers. For this kind of kebab-style grilling, you'll slice the cleaned but unpeeled vegetables crosswise into rounds that are 1/2 inch thick. Alternatively, chop the rounded tops and bottoms off the squash and run your knife down it lengthwise, creating planks that are about 1/2 inch thick. The longest of the three sliced styles are zucchini halves, which have been sliced in half lengthwise into long "boats."
Although you can marinade zucchini and other vegetables before putting them on the grill, you'll probably get just as much flavor drizzling the cooked squash with a a vinaigrette after it comes off the grill. Pre-grilling preparation of the sliced zucchini, therefore, can be as simple as brushing the rounds, planks or halves with olive oil, then seasoning them with salt and pepper.
Kebab-style zucchini takes six to 10 minutes on the grill. The sliced rounds go on soaked wooden skewers, either alternating with one or two other ingredients, or by themselves. Instead of piercing them through the center, which will cause the kebabs to roll, skewer each zucchini round lengthwise so that the kebabs will lay flat. Flip each zucchini kebab after three to five minutes, then cook on the other side an equal amount of time.
Zucchini planks will take less time to grill than rounds of the same thickness, because they have more surface area exposed. Check them at the two- or three-minute mark to see if they're ready for flipping, then cook for the same amount of time on the other side. Planks that are about 1/2 inch thick should be sturdy enough to flip using tongs, be keep a supporting metal spatula nearby, just in case.
Halved zucchini take a little longer to grill, at about 12 minutes total grilling time. The substantial halves are the best shape to use if you want to top the squash with cheese. Help the thick pieces cook more evenly by scoring the top diagonally in lines that are about 1 inch apart. Start with the halves placed cut side down on the grill, and flip after about six minutes. For cheesy zucchini, carefully place grated cheese on top of each half, cover the halves with foil or close the grill's lid, and cook for about one minute longer.