- vegetable-oil cooking spray
- 1 1/2 pounds red onions (about 3 medium), each cut into 8 wedges
- 2 tablespoons balsamic vinegar
- Preheat oven to 450° F. and lightly coat a shallow baking pan with cooking spray.
- Arrange onions in one layer in pan and roast in middle of oven, stirring occasionally, until golden brown and just tender, about 15 minutes. Drizzle vinegar over onions and roast until most of vinegar is evaporated, about 3 minutes. Season onions with salt and pepper and keep warm, covered.