Cut the ham into fine strips. Mix eggs, milk, some salt and nutmeg. Add ham and put the egg mixture into a small, greased, heat-resistant mould. Place the mould in a bain-marie and bring to the boil almost to the boil.
Allow to set at low heat for about 40 minutes. In the meantime clean and slice the mushrooms. Heat the fat in a pot and fry the mushrooms in it. Season with salt and pepper and add 600 ml water.
Bring to the boil, add yeast stock and simmer for 1-2 minutes. Wash chives, dab dry and cut into small rolls. Carefully turn out the eggs and cut into rhombuses or cubes.
Spread the eggs and broth in 4 deep plates and serve sprinkled with chives.