1: Preheat oven to 180-c.

2: First, season the pork all over with table salt. Pay particular attention to the skin to help the crackling along.

3: Roast the pork in the oven for three hours, then rest it for 45 minutes before serving.

4: While the pork is resting, take the rhubarb and slice it into 2cm pieces.

5: Place the sliced rhubarb in a pan, and add the sugar, the lemon zest and a splash of water.

6: Place the pan over a very low heat and cook until the rhubarb softens.

7: Once the rhubarb mixture is cooked, blend it and pass through a fine sieve - it should be quite thick at this point so this hight take some time.

8: Finally, return the rhubarb mix to the heat and slowly stir in the diced butter until it is fully incorporated.

9: Serve the pork with the rhubarb sauce, roast potatoes and buttered vegetables.