In a large skillet heat the olive oil. When the oil is hot, add in the prepared veggies and saute until they're tender and slightly browned. Add the minced garlic during the last minute or two of cooking time. Transfer the veggies to a large pot.

Brown the sausage in the same skillet and drain it well after cooking, then add it to the soup pot along with the stock, sauce, red pepper flakes and most of the pepperoni, saving a few to use as garnishes.

Bring the soup to a boil and then reduce the heat to a gentle simmer. Cover the soup pot with the cover slightly askew so some of the steam can escape while it cooks. Simmer, stirring frequently, for 20 to 30 minutes.

Ladle the hot into bowls.

Top each bowl with some of the Mozzarella, a few slices of pepperoni and a little basil. Let the bowls rest for just a few minutes before serving.

Serve with garlic bread or breadsticks.