Cook the lentils in boiling water for 20-30 minutes until al dente. Peel and clean the carrots. Clean the leek and wash thoroughly. Peel onion and garlic. Cut prepared vegetables into fine cubes.
Heat 1 tablespoon of oil and sauté the diced vegetables for about 5 minutes, turning them over. Add tomato paste and stir in. Season to taste with marjoram, salt and pepper. Peel and slice the sausage. Heat 2 tablespoons of oil in a frying pan and fry the gnocchi for approx. 6 minutes while turning.
Remove the gnocchi and keep warm. Fry the sausage slices in the frying fat for about 4 minutes while turning. Pour lentils into a sieve. Add lentils and stock to the vegetables, bring to the boil and simmer for another 5 minutes.
Place the gnocchi in the sausage pan and fold in. Arrange gnocchi and lentil vegetables on plates.