Fried, baked, or raw, onions enhance many dishes; or they can play a starring role as a delicious main ingredient.
In a medium saucepan, combine onions, cut into 8 wedges each (trim core if pieces won't separate), thyme, and olive oil. Season with coarse salt and ground pepper; toss to combine.
Cover and cook over medium-low, stirring occasionally, until onions release their moisture, 30 to 35 minutes.
Reduce heat to low; leave cover on, and cook onions until golden, stirring occasionally, about 10 minutes.
Stir in balsamic vinegar; cook until syrupy, 1 to 2 minutes.