Peel, wash and cut the potatoes into pieces. Clean, wash and cut the leek into rings. Drain the corn. Melt the fat in a pot. Steam approx. 1/2 leek for approx. 3 minutes while turning until colourless.
Add the corn, except for a little to garnish, and the potatoes and steam briefly. Add stock and cream, simmer at medium heat for 15-20 minutes.
In the meantime, wash the chives, shake them dry and, except for a few stalks for garnishing, cut them into fine rolls. Cut cooked ham into square pieces. Heat the oil in a frying pan. Fry the ham for about 3 minutes while turning it.
Drain on kitchen paper. Finely puree the soup, season to taste with salt, pepper and nutmeg. Add the remaining leek and boiled ham and leave to stand for 3-4 minutes. Arrange soup in cups. Garnish with chives and corn.