Mix the flour and salt in a bowl. Beat the milky water with the eggs, pour in all at once, then mix with a risotto spoon and beat until the dough turns glossy and starts to bubble. Cover and leave to stand at room temperature for approx. 30 mins. Bring the stock to the boil in a large pan. Press the dough in batches through a spaetzle sieve into the stock. As soon as the spaetzle rise to the surface, remove them with a slotted spoon, drain and keep warm.
Heat the oil in a pan, sauté the leek. Add the remaining vegetables and continue to cook for several minutes. Pour in the wine, bring to the boil, reduce the heat, simmer for approx. 8 mins. until the vegetables are al dente. Add the oregano, season, stir in the sour single cream. Mix the sauce with the spaetzle, serve immediately.