1Place the ham into the pressure cooker and cover with cold water. Place over high heat and bring to the boil without the lid. As soon as the water has boiled, drain and discard the water. Rinse the pan then add the onion, peppercorns and bay leaves. Cover with about 3 litres fresh cold water, making sure the pan is not filled above the half way mark. Close the lid and set over high heat. Bring to pressure and as soon as pressure is reached (the indicator will pop up), reduce the heat to the minimum to maintain pressure and time for 55 minutes. When the time is up, turn off the heat allow the pressure to drop naturally until the pressure indicator has dropped - this could take a good twenty minutes. See instruction booklet for details
2Open the lid, remove the ham onto a large plate and allow to cool slightly. Pour the stock into a large bowl or jug and set aside. Wash the pan
3Once the ham is cool enough to handle, remove the skin and fat, take the meat off the bone and shred with two forks. Set aside
4Place the clean pan over medium heat then add 1 tbs vegetable oil. Fry the onion, carrot, celery, potato and leeks for 3-4 minutes. Add the split peas, herbs and about 2½ litres ham stock. Make sure the pan is filled only to the half way line or below. Add another teaspoon of oil to stop the peas from foaming too much during cooking
5Close the lid and set over high heat. Bring to pressure and as soon as pressure is reached (the indicator will pop up), reduce the heat to the minimum to maintain pressure and time for 15 minutes. When the time is up, turn off the heat allow the pressure to drop naturally for 20 minutes, then carefully use the valve to release any remaining pressure. See instruction booklet for details
6Allow the soup to cool for a few minutes then use a stick blender to half-puree the soup, allowing some lumps to remain. Stir in most of the parsley and add back most of the shredded ham, reserving some of each for garnishing
7Serve the soup with crusty bread and black pepper and freeze the leftovers in portions for another day. TIP: There is a generous amount of ham in the soup so if you like, you could save some of the meat for another recipe, making it even better value!