Put the flour, salt, eggs and water in a bowl and whisk vigorously for about 10 minutes until air bubbles appear. Now let the dough rest for 10 minutes, then beat vigorously again. The dough should be able to steep without tearing.
Place portions of the batter on a spaetzle board and scrape the spaetzle into a large saucepan with boiling salted water. When a portion floats on top, take it out and drain in a colander. In between, add a little butter to the finished spaetzle so that they don`t stick together. Do this until the batter is used up.
Bacon Sauce:
Melt the butter in a saucepan and add the bacon along with the onions and garlic. Fry lightly, add the flour and sauté again a little. Deglaze with milk or cream and season with salt and pepper. Depending on the consistency you prefer, I add a little more stock and let everything simmer for 5 minutes.
Garnish with chopped herbs or add some cheese to the sauce, if you like.