In a large baking dish add the parsnip, baby beetroot and carrot and garlic. Drizzle with olive oil, season with salt and pepper and a few sage leaves.
Place the beetroot to one side of the dish to ensure they do not stain the other vegetables while cooking. Bake for 25-30 minutes.
In the meantime, season the chicken with salt and pepper. Heat oil in an ovenproof pan and seal the chicken, skin side down. Turn over and cook for a further 5 minutes.
Now add the mushrooms around the chicken add the remaining sage and bake in the oven for 15-20 minutes.
Remove the vegetables and chicken from the oven and allow the chicken to rest for 10-15 minutes before slicing.
Place all the vegetables in a large bowl, including the mushrooms, garlic and sage leaves. Now add the beetroot leaves and hazelnuts, balsamic and olive oil. Toss to coat all the vegetables in the dressing.
Place on a platter and finally arrange the sliced chicken on top.