Step 1

Get out a shallow dish in which the scored pork will fit snugly and in it whisk together the tahini, soy sauce, lemon and lime juice.

Step 2

Sit the pork on top, skin-side up. You should find the marinade covers the underside and most of the sides, but doesn’t touch the rind: that’s what you want.

Step 3

Leave the pork in the fridge to marinate overnight, covered with foil, and then take out to return to room temperature before it goes into the oven.

Step 4

Preheat the oven to 150°C/130°C Fan/gas mark 2/300ºF.

Step 5

Get out a shallow roasting tin and line with foil.

Step 6

Transfer the pork to the roasting tin - some of the marinade will stay on the pork, and that's what you want - and cook it uncovered for 3½ hours, then turn the oven up to 250°C/230°C Fan/gas mark 9/450ºF and cook for a further ½ hour to let the skin crisp to crunchy burnished perfection.