Clean or peel and wash the soup greens. Cut carrots and celery into small cubes, cut leek into rings. Peel and finely dice onions.
Heat 1 tablespoon of oil in a large pot. Brown the soup greens and half of the onions in it. Rinse lentils and meat. Add 1 1/2 l water and thyme to the vegetables. Bring everything to the boil, cover and simmer for about 25 minutes.
Peel, wash and chop the potatoes. Dice plums. Add both to the lentils and cook for another 15 minutes.
Wash the parsley, shake dry. Put something aside for garnishing. Coarsely puree the rest with nuts and remaining onions, stirring in 3-4 tbsp. oil. Season pesto with salt and pepper.
Take the meat out of the soup and dice it. Put back into the soup. Season soup with salt, pepper and vinegar. Arrange in deep plates and add some hazelnut pesto. Garnish with parsley.
Add the rest of the pesto.