For the lentils with bacon and spaetzle, first sauté the finely chopped onion in butter and make a light roux with flour. Then add the lentils and simmer gently for about 10 minutes.
If the consistency is too tough, add some spaetzle water. Finally, season with salt, pepper, mustard and lemon. In the meantime, fry the bacon over low heat until crispy.
The easiest way to prepare the spaetzle is in a food processor. To do this, put all the ingredients in the mixing bowl and mix until the dough bubbles. Then pass the finished dough through a spaetzle strainer or a spaetzle slicer into boiling salted water.
Once they float to the surface, they are ready. Serve the lentils with bacon and spaetzle.