Here are a few hints for grilling vegetables…
First start with a hot fire. Then marinate them a bit in olive oil, fresh herbs, and or balsamic vinegar.
Trim away roots and greens from the leek, leaving the white shaft. About 1 inch above the root end, cut through the leek lengthwise so that the root end is the only part holding the two halves together. Wash any soil from between the leaves and then cut the leek completely in half. If your leeks are more than three quarters of on inch in diameter, boil some water and blanch them in it for one minute. Smaller leeks generally don’t need blanching. Brush with olive oil and lay right on the grill for at least 4-5 minutes a side. Some blackening is ok as the heat will release the sugars in the leek.
Peppers can be done whole or halved with the seeds and veins removed. Either should be brushed with olive oil and put on high heat. To really roast peppers leave them on each side until the skin blackens and separates from the flesh. After the pepper is blackened all the way around put it immediately into a paper bag for 10 minutes, this steams the peppers further and make removing the blackened skin easier.
Eggplant can be cut into large rounds half an inch thick and oiled or roasted whole like the peppers. If you like baba ganouge (a middle eastern mixture of roasted eggplant, tahini, garlic and lemon) roasting eggplant like this is the way to make your own! Whether roasting or grilling the slices, be liberal with the olive oil and make the fire hot. Like the leek and the peppers, don’t be afraid of some blackening, the sweet richness of the vegetables will be complimented by the smokiness.