Heat the 2 teaspoons of oil in a Dutch oven over medium heat. Add the chicken and cook, stirring until just cooked through, 3-5 minutes. Transfer to a plate.
Add the remaining 3 teaspoons of oil to the pot. Add the onion, parsnips, carrots, rosemary, salt, and pepper, and cook, stirring often, until the vegetables begin to soften, 3-5 minutes.
Add the broth and apples; bring to a simmer over high heat. Reduce the heat to maintain a simmer, and cook, stirring often, until the vegetables are tender, 8-10 minutes. Return the chicken to the pot and stir in the vinegar.
