Heat a 5-quart stock pot or Dutch oven over medium heat. Add the garlic infused olive oil and Italian sausage. Break the sausage into small pieces and cook until no pink remains.
Add the diced green pepper to the pot and stir. Cook for about 5 minutes, until slightly softened.
Pour in a small splash of chicken broth and scrape the bottom of the pot to release any browned bits. Add the remaining chicken broth.
Stir in the diced tomatoes, tomato sauce, drained mushrooms, and drained black olives.
Add the Italian seasoning, white sugar, sea salt, and crushed red pepper flakes. Stir, bring to a gentle simmer, and cook for about 5 minutes, stirring occasionally.
Ladle into bowls and top with shredded mozzarella, grated Parmesan, and fresh basil before serving.
Store leftovers in an airtight container in the refrigerator for up to four days.
Notes
Note 1: For a lower fat option, use turkey Italian sausage. Note 2: If you cannot find mini pepperoni, chop regular-sized pepperoni into fourths. Note 3: For low FODMAP, use a chicken broth without onions or garlic. Note 4: For the ultimate melt, shred the mozzarella cheese yourself. Low FODMAP Notes: Low FODMAP ingredient information is based on the Monash University Food App and FODMAP Friendly App testing results.