1. Preheat oven to 450 degrees. On a rimmed baking sheet, toss parsnips with 1 tablespoon oil; season with salt and pepper. Push parsnips to sides; place chicken in center, and season with salt and pepper.

2. Roast, tossing parsnips occasionally, until an instant-read thermometer inserted in thickest part of breast (avoiding bone) registers 165 degrees, 30 to 35 minutes

3. Meanwhile, cook chard: In a large skillet, heat remaining tablespoon oil over medium. Add stalks, and cook, tossing, until crisp-tender, 3 to 4 minutes. Add as many leaves to skillet as will fit; season with salt and pepper, and toss. Continue to add leaves in batches as there?s room in skillet. Cover and cook, tossing occasionally, until chard is tender, 3 to 5 minutes.

4. Remove chard from heat, and stir in vinegar. Serve roast chicken with parsnips and chard