Slice onions in half, wash off, and pat dry
Slice each end off
Start slicing down but keep the rounds in tact
Lay directly into cast iron skillet
Add balsamic vinegar, teriyaki sauce, worcestershire sauce
Mince two cloves of garlic and throw into pan with onions, vinegar, and sauces
Layer each onion with brown sugar letting the brown sugar sit on top to cook down
Salt and pepper to taste if you like
Let cook on medium heat until onions are soft and caramelized. Sauces will start to evaporate a bit leaving the onions with a caramelized texture
Use immediate or store in an air tight container for up to 5 days