- 3 red onions , cut into 1/4-inch slices
- 3 yellow onions , cut into 1/4-inch slices
- 1/4 cup extra-virgin olive oil
- 3 tablespoons balsamic vinegar
- 1 teaspoon salt
- 1/2 teaspoon freshly ground pepper
Place the onion slices on grill (flame should be low) by using a vegetable tray or by laying directly on grill (be careful not to let them fall through; rings will break up). Turn once or twice until tender; grill about 20 to 30 minutes.