Heat oven to 400. In a dutch oven or other oven safe heavy pot, heat oil over high. Sprinkle chicken breasts with salt, pepper, garlic powder, onion powder. Place skin side down and cook until skin is well browned. Flip and brown on the bottom. Reduce heat to medium.
Add the onion, garlic, and rosemary and stir a bit so it gets to the bottom of the pot. After a minute, add the wine and allow to boil for a minute. Then add the broth and vinegar. Season with more salt and pepper.
Cover and place dish in the oven for 30 minutes. After 30 minutes remove the lid and continue cooking until chicken is fully cooked through and tender (30-45 more minutes) allowing the skin to crisp up more. Keep an eye on the sauce to make sure the liquid isn't all evaporating. Add a bit more water if needed.
Once the chicken is cooked, remove pan from the oven and transfer chicken to a plate. Heat the pan over high to thicken the liquid. If you still have a lot of liquid left, mix a tbsp of cornstarch with a tbsp of water and whisk some of this into the sauce until it thickens up. Serve chicken with sauce over the top, and more on the side for dipping.