Rinse and sort through the dry beans. Check for any unwanted debris and discard.

Remove a pound of sausage from its casing. In a 6 quart-dutch oven, add a teaspoon of olive oil, and cook sausage until golden brown. Use a slotted spoon to transfer with a paper towel lined plate.

To the leftover sausage grease, add the onion, celery and carrot. Stir, and cook for several minutes until softened.

Add the minced garlic, contents of the Italian seasoning packet, red pepper flakes, and salt and pepper to taste. Give it a stir. Add the cooked sausage back to the pot, along with the dried beans, chicken broth, and diced tomatoes. Do not add the pasta shells. You'll add those towards the end of the cooking time.

Place the lid on the pot and simmer on low heat for about 3 to hours, or until beans are tender. Remove lid, and stir in the pasta shells and cook for about 10 minutes until pasta is al dente.

Top with grated Parmesan cheese and chopped parsley, if desired, and serve with a loaf of Italian bread.