Pre-heat the oven to 200ºC/390ºF
Give the garlic cloves a bash with a knife and then put them into the cavity of the chicken, along with half the lime.
Tie the legs together with some string or cooking twine. Then place the chicken in a deep, large metal roasting tin.
Mix 2 tsp of the curry paste with the oil and rub it all over the chicken.
Place the potatoes around the chicken (I leave them whole), pour over the chicken stock and then loosely cover the tin with foil.
Roast for 30 minutes, then remove the tin foil and cook for a further 40 minutes.
Take the chicken out of the tin and set it aside to rest.
Put the tin with the potatoes in, on the hob and add in the remaining curry paste, the coconut milk, brown sugar and fish sauce.
Stir well and cook for 5 minutes until it has thickened slightly.
Serve the chicken with the massaman gravy, the potatoes and some plain boiled rice.
Garnish with fresh coriander and the remaining lime.