Rinse the lenses in a sieve under running water and
Peel onion and chop finely. Wash the leeks, cut them in halves and cut
them transversely into strips of 1 cm. For the marinade mix vinegar,
salt, pepper and marjoram. Stir in 4 tbsp. oil. In the remaining oil
sautée leeks and onion, fold in lentils. Pour mixture into a bowl, mix
well with the marinade and marinade for about 10 minutes. Divide the
trout fillets and mix them with the salad.