Place the ham in a large, deep saucepan. Peel and halve the onion, slice the apples in half, trim and scrub the carrots, cut the celery in half and add to the pan. Add the parsley stalks, bay leaves, black peppercorns and juniper berries, then pour in the cider and a litre of water. The ham may not be entirely submerged in liquid – no matter – it will partially cook in its own steam, and you can turn it over during cooking.
Bring the ham to the boil, then lower the heat to a gentle simmer, partially cover with a lid and leave to cook for 1 hour. Turn the ham halfway through cooking. Remove from the heat and set aside to rest for 10–15 minutes. Remove the ham from its liquor and slice thinly. Serve with artichokes and red cabbage and spoonfuls of its own apple-scented cooking liquor.