Put the pork skin side up on a rack in a large roasting tray and cook in a cool oven – 150C/fan 130C/gas 2 for about 31/2 hours.

Meanwhile, put the shallots (with skin) in a pan, cover with water and bring to a simmer. Cook for 1 hour, then drain and cool.

Cut each shallot in half lengthways through the root. Peel off the skin – still leaving the ‘half’ root in place.

Heat a little oil and butter in a large pan and fry the cut side of the shallots until they are nicely browned. Turn and colour the other side. Serve with the pork.