Cook the spaetzle in plenty of boiling salted water for approx. 15 minutes according to the instructions on the package. Pour into a sieve, rinse ice cold, drain well and allow to cool.
Clean the leek, slit lengthways, rinse thoroughly and cut into fine rings. Blanch 1/2 minute in boiling salted water, then rinse ice cold and drain well.
Cut the streaky bacon into small cubes and fry them in a non-fat frying pan until crispy. Remove and drain on paper towels.
Clean, wash and cut the bell pepper into small cubes.
In a large bowl, stir together the vinegar, oil, mustard, salt and pepper until you have a creamy marinade.
Add the spaetzle, diced bacon, leek rings and diced paprika and mix.