Grilling vegetables over the dry heat of a gas grill fire gives them a smoky, savory flavor while bringing out the natural sugars making them taste sweet. The hot temperature quickly seals the outside of the vegetables, allowing the inside flesh to cook in its own moisture. The result is a different but more complex flavor than that of vegetables cooked by boiling or steaming. In addition, grilling seals in vitamins and minerals that might otherwise be cooked away. Some vegetables are simply so delicious grilled you won't consider cooking them any other way. 

About Grilling Vegetables

Most vegetables cook beautifully on the grill with just a minimum of preparation or attention. As is true when grilling anything, the most important skill to be mastered is patience. Vegetables contain a fair amount of natural sugar, which is why they are sealed quickly and acquire a light crust when cooked by a dry heat method. But it is this sugar content that will cause them to burn if the fire is too hot. Fruit, which contains even more sugar, will require an even lower heat.

Unless the peel is thick and woody, fibrous, or tough, most vegetables will not need to be peeled. If they are relatively small, vegetables are delicious cooked whole, but are also easy and quick to cook when sliced or cut into chunks first. A good standard slice thickness is one-third to one-half inch. Bite-sized chunks (three-quarter-inch cubes) are the easiest to skewer.

The cooking grid should be lightly oiled to prevent sticking, and the vegetables will brown more evenly when lightly brushed with oil. Olive oil and other vegetable oils burn at a very high temperature and are thus good choices for brushing on foods to be grilled. Nut oils are delicate and burn at low temperatures. They should be used carefully since they will give food a burned and bitter taste if the heat is too hot. Some vegetables do not need any oil.

If your grill is large enough to accommodate it, heat so it has a cooler spot and a hotter spot. This allows you to sear the vegetables over the hotter side and move them to a less intense part of the grill to finish cooking. On a gas grill, preheat one side and turn it off for the cool side; leave the other burner on low for the hot side. As a general rule, most vegetables require a total cooking time of between 15 and 20 minutes and cook more evenly on a covered grill. Testing doneness with a wooden skewer is a very reliable method -- if the vegetable is tender when pierced with the skewer, it is likely to be done.

Vegetables, whether sliced or whole, can be grilled right on the cooking grid but can also be threaded onto metal or wooden skewers, or arranged in a hinged grill basket. Some vegetables are too small and delicate to be grilled directly over the fire; these can be wrapped in foil, but pierce the foil with holes to allow smoke to penetrate the packet and flavor the food.

Open grilling is cooking without a hood or top over the grill. The grill is hotter when the hood is down. Food browns quickly and, therefore, needs to be somewhat thinly sliced so that it cooks through in a short time before over-browning. If skewered, the vegetables should be sliced into bite-sized chunks. The hood can control your cooking time. For faster cooking, keep the hood closed. For longer cooking, open the hood.

Closed grilling is not recommended for whole vegetables.