Clean and wash the leek, carefully peel off the outer leaves (5-6 per stalk). Put them into a large pot with boiling salted water and let them simmer for about 2 minutes. Carefully lift out with a skimmer, drain and allow to cool.
Cut the remaining leek into rings. Clean, wash and finely dice the peppers. Peel onion and chop very finely. Add herb cream cheese, marjoram, onion and 1/3 of the paprika cubes and mix.
Place two leek leaves on top of each other to make 8 roulades. Spread the cream cheese paprika mixture on top and roll up tightly. Tie together with kitchen string. Heat the oil in a large frying pan and carefully fry the roulades in it while turning.
Remove from the pan and keep warm. Add the remaining peppers and leek rings to the frying fat and fry while turning. Season with salt, pepper and paprika and deglaze with stock. Bring to the boil, cover and simmer at low heat for about 7 minutes.
Bring to the boil, stir in the sauce thickener, bring to the boil again and season to taste with salt, pepper and paprika. Add roulades again. In the meantime, put the noodles in boiling salted water and cook for about 11 minutes. Then pour into a sieve, quench and drain.
Arrange noodles and 2 roulades each with sauce on plates and serve garnished with marjoram as desired.