directions

To cook the ham, place the fillet in a large deep saucepan and cover with water. Bring to the boil, then drain. Add fresh cold water and bring to the boil again. Simmer for 50 minutes (approximately 20 minutes per 450g). Preheat the oven to 180°C/gas mark 4. Drain the ham, place in a roasting dish and remove the skin, leaving a layer of fat. Score the fat and spread with the mustard then sprinkle over the sugar. Bake for 20 minutes until caramelised.

Meanwhile, peel the potatoes and place in a large pot covered with cold water. Bring to the boil and simmer for 20 minutes. While the potatoes are cooking, prepare the leeks by removing the dark green ends. Slice down the length, keeping the root intact. Gently separate the leaves and wash thoroughly. Slice into thin strips. Melt the butter in a large frying pan and add the leeks, cook slowly for 10 minutes. Add the milk and continue to cook until the leeks are soft. Drain and mash the potatoes and add the milk and leeks. Season well. Slice the ham and serve, hot or cold, with the leek mash.