Add 16 ounces of Italian sausage into a large pot over medium heat and cook until cooked through and browned
Transfer the sausage onto a plate and set aside for now
Add the diced onions, carrots, celery and minced garlic into the pot and cook for about 8 minutes or until they have softened
Add 2 tablespoons of tomato paste, 1 tablespoon of dried Italian herbs, a big pinch of salt and black pepper and an optional 1/2 teaspoon of crushed red pepper flakes and mix to combine
Add 6 cups of chicken or beef stock, 30 ounces of fire roasted tomatoes, a bay leaf, 1 1/2 cups of brown lentils and an optional parmesan rind and bring the mixture to a simmer
Add the browned sausage, reduce the heat to medium low, cover the pot and cook for 30 minutes or until the lentils are tender
Before serving, remove the bay leaf and parmesan rind and stir in the fresh herbs and parmesan
Taste test and add additional salt and black pepper, if necessary
Store leftovers in an airtight container and reheat with additional stock if necessary