Mix the spelled flour, salt and nutmeg. Add the water, eggs and oil and knead well to make the dough smooth. Let rest for 1/2 hour.
In the meantime, bring the water to the boil in a large saucepan and scrape in the spaetzle dough using a spaetzle slicer, grater, press or board. But not too much at once, otherwise they will stick together.
When the spaetzle swim at the top, remove them with a skimmer and rinse in a bowl of cold water. Drain well on a sieve.
When the spaetzle are dry, toss with butter, salt and nutmeg and serve.