To start, prep all the ingredients first. I recommend the pepperoni stick because you can cut big hearty pieces for the soup. Prep everything then move to the next step.
In a large pot, cook the Italian sausage until fully cooked then remove from the pan.
Add in the sliced mushroom, onion and garlic. Cook until all are soft, fragrant and have changed color. Then, toss in the basil and cook within the ingredients for about 15 seconds and lower the heat to medium-low.
Next, add in the crushed tomatoes and stir everything before adding in the listed seasonings.
Allow the soup to simmer for 30-45 minutes allowing all the flavors to come together.
Turn the oven on broil right when the soup finishes.
Grab some oven safe bowls then add in the soup. Top with the bread and a helping of mozzarella cheese on each bowl. Place into the oven until the cheese is bubbly and melted.
Allow to cool before serving because everything will be extremely hot, enjoy!