Fresh vegetables are naturals for grilling. In summer, grilling becomes the fastest, easiest way to cook dinner. It usually involves advance preparation, quick results and minimal cleanup.
The key to tasty grilled vegetables is the marinating and basting mixture. I use a mixture of olive oil and balsamic vinegar, a combination that gives a rich flavor without too much fat. Most vegetables marinate well, and the mix can be adjusted to the weekly bounty from garden or farmers' markets. My best success has been with thick slices of eggplant, halved cooked artichokes, thin slices of raw sweet potatoes, quartered Vidalia or Maui sweet onions, halved cooked red potatoes and sections of corn on the cob.
I place my selection of cut-up vegetables in a freezer-weight, plastic, self-sealing bag along with the marinade, then seal the bag and shake well to coat the vegetables evenly. I refrigerate the mixture (in the bag) at least 1 hour; even overnight is fine.
Before grilling, I turn the bag at least once to thoroughly coat each vegetable again. This guarantees that the vegetables will stay moist in the heat of the grill. Give the grill five minutes to heat thoroughly; if using a gas grill, keep the flame at medium-high. A lacquer-coated grill-wok or grill-pan (available at cookware stores) works best for smaller vegetables, such as mushrooms or onion slices that tend to slip through the grate.
Most of the vegetables take five to 10 minutes to cook through; even raw corn on the cob cooks fast over that intense heat. But they need to be basted to prevent them from drying out. Use the marinade from the bag and generously baste them every few minutes. You can use the grilled vegetables as a meal in themselves, perhaps served with couscous or rice pilaf. I also love them on top of a green salad with thinly sliced goat cheese.