Preheat the oven to 180C/gas 4.Set a large saucepan of well-salted water on to boil. Once boiling, add the chard whole. Cook for three minutes, then drain and run under very cold water so it immediately stops cooking.
Leave to drain, then use your hands to squeeze all the moisture out of the chard. Sit the squeezed chard on a bit of kitchen roll or a clean tea towel to catch any remaining moisture.
Beat the cream with the eggs, nutmeg, Parmesan and a pinch of salt. You could also add some white pepper if you like.Finely chop the chard, then stir it through the cream.
Pour the mixture into a small oven dish. Lay slices of cheese on top. Put in the oven and bake for about 30 minutes, or until there is only the faintest wobble left in the centre of the dish. Leave to cool and firm up a bit out of the oven for about six minutes before serving.