- MAKE THE SOUP BASE: In a large pot over medium-high heat, warm the olive oil. Add the pancetta and sauté until lightly browned, about 2 minutes. Add the onion, garlic, carrot, celery and sage and sauté until the vegetables are softened, about 3 minutes.
- COOK THE LENTILS: Stir in the lentils and tomatoes and cook, stirring occasionally, for 5 minutes. Increase the heat to high, add the 6 cups broth and bring to a boil. Add the 1 tablespoon salt, reduce the heat to medium-low and simmer, partially covered, until the lentils are nearly tender, 30 to 40 minutes. Add more broth if the soup starts to dry out.
- COOK THE PASTA: Add the pasta to the lentils. Cook, stirring occasionally to prevent sticking, until the pasta is not quite al dente, about 2 minutes less than the package instructions. The pasta will continue to cook in the heat of the soup. Season with salt and pepper. Ladle the soup into bowls and serve immediately.