Gather all ingredients.
Cut pepperoni slices in half.
Cook pepperoni in a 6-quart soup pot over medium-high heat until pepperoni starts to crisp, stirring occasionally, about 5 minutes.
Remove pepperoni from pan and drain on paper towels. Set aside.
In the same pot, cook sausage over medium-high heat until cooked through, about 5 minutes.
Add onion and peppers; cook until crisp-tender, stirring occasionally, about 5 minutes.
Add tomatoes, tomato sauce, beef broth and Italian seasoning to the pot. Bring mixture to boiling over medium high heat. Reduce heat and simmer, covered, for 10 minutes, stirring occasionally.
Top each serving with crispy pepperoni, mozzarella, and Parmesan cheese.
