To prepare the vegetables, peel and trim the shallots, allowing them to fall into their natural segments, if they have any.
Peel the pumpkin, parsnips and carrots and cut them into cubes of equel size, about 2.5cm across, large pieces.
Place the olive oil in a roasting tin and heat in the oven for a few minutes. When hot, remove from the oven and add the prepared vegetables and garlic cloves. Stir to combine and coat evenly in the oil. Lay the sprigs of rosemary amongst the vegetables, season with salt and pepper and roast for 30 minutes.
Meanwhile, smear the mango chutney over the exposed meat on the racks of lamb. Press the chopped parsley onto the chutney coating and place the racks of lamb on a metal rack in a roastng tin.
When the vegetables have been cooking for 30 minutes, give them a stir and return to the oven, placing the sepatate roasting tin of lamb in the oven at the same time.
Roast for 15-20 minutes (15 minutes will give lamb pink lamb, if you want it well done roast for 25 minutes).
Remove the vegetables from the oven after 15 minutes or when they are done to your liking.
Discard the rosemary before serving the vegetables hot with the roast lamb.