Peel and finely chop the onion. Clean, wash and slice the leek. Clean, peel and cut carrots into sticks. Heat 2 tablespoons of oil in a pot and fry the onion in it.
Add leek, carrots and brown lentils, season with salt and pepper and steam for about 5 minutes while stirring. Sprinkle with curry and sauté. Deglaze with broth and bring to the boil. Cook over low heat for 35-40 minutes, stirring occasionally.
Add the red lentils about 15 minutes before the end of the cooking time and cook. In the meantime cut the sausages into slices. Heat the remaining oil in a frying pan and fry the sausage slices vigorously on all sides.
Add to the stew shortly before the end of the cooking time and stir in. Season again and serve on plates.