Add the leeks to the pot and cook, stirring occasionally, for 6 minutes. Add the rosemary and carrots and cook for another 5 minutes. Stir in the lentils and tomato paste and continue stirring to make sure that everything is evenly coated with the tomato paste. Turn the heat to high, add the wine, and bring to a boil. Cook for 1 minute. Add the chicken stock and turn the heat to low. Add half of the parsley, season with salt and pepper, and simmer, covered, for 45 minutes to 1 hour, or until the lentils are cooked (they should be al dente, not super-soft or falling apart). Taste and adjust the seasoning, adding more salt and pepper if needed.