Whisk the chipotle with the tomato purée and sugar, then rub 2 tbsp of this over the underside of the pork.

Whisk the rest with 300ml water to make a marinade.

Lay the pork in a roasting tin and pour in the marinade – don’t pour it over the skin.

Cover with foil and roast for 3 hrs or until tender.

About 30 mins before it’s ready, scatter the pineapple round it, baste in the juices, re-cover and put back in the oven for the remaining 30 mins.

2)Set the grill to high.

Move the pork to another tin or baking tray, skin-up, and grill for 10 mins or until the skin blisters and crisps – keep a close eye, it can burn quickly.

When the crackling is crisp, take out and rest for 20 mins, cut into eight slices and return to the tin with the pineapple and marinade and coat well.