A simple balsamic-glaze turns semisweet cipollini onions into a sophisticated side dish. Also Try:Potato-Wrapped Halibut, Sauteed Spinach
Preheat oven to 400 degrees.
Heat olive oil in a medium ovenproof skillet over medium heat. Add onions, stem side down, and cook, until lightly browned, 2 to 3 minutes. Turn and continue browning on opposite side, about 2 minutes more. Season with salt and pepper.
Add vinegar and sugar; cook, until slightly syrupy, about 2 minutes. Add chicken broth, thyme, and garlic; bring to a boil. Transfer skillet to oven and roast until onions are easily pierced with the tip of a sharp knife, 15 to 20 minutes.