Clean or peel and wash leek and carrots. Peel onion and garlic. Cut everything into fine cubes.
Heat 1 tablespoon of oil in a saucepan. Fry the diced vegetables, onion and garlic for about 5 minutes. Stir in tomato paste, sweat briefly. Rinse lentils with cold water, add. Add a good 1/2 l water and marjoram.
Bring to the boil and simmer covered for 40-45 minutes.
Peel the skin off the sausage. Cut the sausage into thin slices. Heat 1 tablespoon of oil in a large pan and fry the sausage in it. Take it out. Fry the gnocchi in hot frying fat for 5-7 minutes, turning them over.
Season lentils with vinegar, salt, pepper and sugar. Mix with gnocchi and sausage.