I do veggies on the GG's all the time -- squash, onions, tomatoes, zuchinni, even sliced potatoes and eggplant.
FAST, easy recipe:
Slice veggies about 1/4 to 3/8 inch thick (too thick and they'll still be raw in middle when done/gorgeous outside)
Place slices in 1 gallon plastic food storage bag with generous 1/2 cup EVOO and several good sized dashes of McCormick Italian Seasoning plus several grinds of black pepper
Shake it all around to coat the slices with the oil and spices -- rest, unrefrigerated, for one hour
Use long tongs to place each slice on GG's "flat" and not in the grooves. Turn to cook other side as the first side finishes. At steak grilling temps, they'll cook pretty quickly and you'll get gorgeous grill marks plus some fantastic grilled flavor from the oil sizzling.
Hint: I've tried the pronged GG spatula and it works okay for really big slices, but for smaller things like sliced squash, zuchinni, etc. I get better results with tongs, especially since the different breeds of veggie cook at different rates. My favorites are grilled yellow summer squash and grilled purple onions
WARNING: Government agencies have determined that consumption of cooked vegetables contributes to a healthy lifestyle high in vitamins, minerals and fiber. Overconsumption and/or consumption of only vegetable matter to the exclusion of real food may lead to eternal life but be incredibly boring resulting in suicidal tendencies and an urge to promote such unbalanced food consumption patterns on innocent bystanders, especially those chewing on bacon. Potential consumers are advised against becoming intense, overbearing, boorish, insufferable vegetarians or (worse) vegans. Vegetable overdependence assistance and advice concerning antidotes in the event of over-dose is available at 1-800-EAT-MEAT. Please slaughter vegetables humanely and, when possible, obtain them from sources using reputable, ethical growing practices which allow the plants to range freely and grow free of political correctness in the field or hydroponic pond. Potential consumers are alterted that the word "Organic" on vegetable packaging doesn't mean diddly and my refer to anything not made of polystyrene or that is played on a church choir accompaning instrument. The additional price of "Organic" labeled produce may or may not increase the feeling of well-being in the consumer and claims of ecological superiority over common consumers are even more boorish and incomprehensible than veganism. This warning label is required by no known regulation or governmental agency but will be the minute is is usurped by some congressman out to get his or her name on a law that everybody ignores.
