3 zucchini (approximately 8 in. long), ends trimmed and cut into quarters, lengthwise
3 yellow squash (approximately 8 in. long), ends trimmed and cut into quarters lengthwise
2 bunches of scallions, washed and trimmed to 8 in. long
2 large heads of fresh garlic, cloves separated and peeled
2 - 3 Tbsp. garlic-infused olive oil
4 - 6 bamboo skewers, soaked in water
sea salt and freshly ground pepper