Preheat the oven to 150˚C.
First, lay 2 onions, carrot, ½ garlic bulb, thyme, rosemary sprigs and bay leave on a roasting tray that will fit the turkey leg.
Then, rub the turkey leg with the mustard, honey, season with salt and pepper. Place the turkey over the vegetables in the roasting tray. Pour around the leg the warm chicken stock and place in the preheated oven for 1 hour. After 1 hour, cover the roasting tray loosely with aluminium foil without pressing on the turkey leg or tightly closing on the roasting tray to just prevent the skin to burn.
Continue roasting for another 2.30 - 3 hours or so until the skin is crispy and the meat very tender.
In the meantime, prepare the parsnip and pear tray bake.
In a large baking tray, add the onion, garlic, parsnip, herbs, parma ham. Drizzle some olive oil and toss to coat on the vegetables.
Roast for 25-30 minutes then add the pear, honey and continue roasting for another 10 minutes until coloured.
Add the blue cheese in the last minutes before serving to soften into the pasnip and pear traybake.
Carve the leg and Serve immediately with the parsnip.