1Heat the olive oil over medium heat in a heavy soup pot or Dutch oven, and add the onion. Cook, stirring, until tender, about 5 minutes. Add the garlic, carrot and celery, and a generous pinch of salt, and continue to cook for another 5 minutes until tender. Add the tomatoes and bouquet garni, and cook, stirring often, until the tomatoes have cooked down somewhat and smell fragrant, about 10 minutes. Add the lentils, water and salt to taste. Bring to a boil. Reduce the heat, cover and simmer gently one hour. Taste and adjust seasonings. Remove the bouquet garni, and stir in the parsley. Serve, garnishing each bowl with Parmesan or Gruyère.
