Mix flour, eggs, approx. 1 teaspoon salt, 1 pinch of nutmeg and mineral water to a thick dough. Let it rest for at least 1 hour. Grate cheese. Chop walnuts
Bring 2-3 l salted water to the boil. Spread the dough in portions on a damp "spaetzle board". Scrape strips into the water with the back of a knife (or press through a spaetzle press). Bring to the boil and cook until the spaetzle rise. Quench and drain
Layer with cheese and nuts in an ovenproof dish. Bake in a hot oven (electric cooker: 200 °C/circulating air: 175 °C/gas: level 3) for 10-15 minutes
Peel onions and cut them into rings. Fry in hot oil. Sprinkle with chives in small rolls over the spaetzle