In a heavy bottom 5 quart pot over medium heat, heat the oil and sauté onions, carrots and celery until softened but not browned, about 7-10 minutes. Add the sausages and break them up with spoon. Saute for three minutes until browned.

Add the lentils and stir to coat well. Heat for 1-2 minutes. Add chicken broth and water and bring to a boil. Reduce heat to medium low and simmer for at least 60 minutes, or up to 90 minutes, or until lentils are soft and tender throughout.

When the lentils are just right, add tomato paste, vinegar and pepper and stir thoroughly. Taste for salt, adding as needed. Turn off heat and add spinach, stirring until completely wilted.

Serve in wide, shallow bowls and garnish with croutons and shaved parmigiano-reggiano cheese. Goes great with a nice piece of crusty bread. Makes 8 starter or 6 entrees servings.