In a large bowl combine seasoning and vinegar. Separate onion rings and add to bowl; toss. Marinate 30 minutes. Place the largest rings (same number as serving size) on a cutting board and insert smaller rings inside leaving some space between rings. Push a skewer through the rings horizontally so that each ring is attached in 2 places on the skewer. Repeat for the remaining onion lollypops. Grill over medium heat for 5-6 minutes per side.
Grilled Balsamic red onions could be served as a side dish or on your favorite grilled entrées.