1 pound Large onion
1 pound Red bell pepper
1 pound Green bell pepper
1 pound Yellow squash
1 pound Zucchini squash
1 cup Olive oil
1/3 cup Italian seasoning
Peel onions and cut top-to-bottom in large wedges. Cut tops from bell peppers, remove core, and cut in large top-to-bottom pieces. Trim ends from squash and cut in diagonal rounds, about 1/2″ thick. Toss all vegetables in a large bowl with olive oil and seasoning, breaking up the onion wedges somewhat. Place in a single layer on a very hot grill (watch out for the flare-ups!) and grill, turning occasionally, until peppers are slightly charred and veggies are tender (about 5 minutes).
Serve immediately. These are also good refrigerated, then microwaved to reheat.