Cut the leek into rings and wash, then cook in a saucepan with water for about 15 minutes. Just before the leek is done, mash and add the stock cube and simmer gently.
Heat a large pan and fry the steaks, season with salt and pepper, add grill & steak seasoning if you like. When the steaks are ready, remove them from the pan.
Pour 1/2 cup of the leek stock into the pan, add the leek, season with salt, pepper and nutmeg and simmer on a low heat, then add 1/2 cup of cream and season to taste again.