Rinse and trim vegetables. Cut a 3-inch portion from the bottom of 6 of the green onions. Save remaining onion tops for another use. Place pattypan squash, zucchini, pea pods, and 3-inch green onion portions in a plastic bag set in a shallow dish.

Finely chop remaining 2 green onions. For marinade, in a screw-top jar combine olive oil, Parmesan cheese, vinegar, finely chopped green onion, oregano, salt, and pepper. Cover and shake well. Pour marinade over vegetables in the bag. Close bag. Marinate vegetables in the refrigerator for at least 1 hour or up to 24 hours, turning bag occasionally.

Drain vegetables, reserving marinade. On 6 long bamboo* or metal skewers, poke vegetables in alternating order. Cook vegetables on the rack of an uncovered grill directly over medium coals for 8 to 10 minutes or until browned and tender, turning and brushing with reserved marinade occasionally. Makes 6 side-dish servings.

If using bamboo skewers, keep them from catching fire or charring by soaking them in water for at least 30 minutes before use.