Preheat the oven to 350 degrees Fahrenheit.
Heat the oil in a large oven proof skillet over medium heat. Add the Italian sausage, breaking it up as you cook. When it is completely broken up but before it has begun to brown, add the green pepper and garlic. Season with salt and pepper. Sauté until the peppers have begun to soften, about 5 to 7 mintues. 1 tablespoon olive oil, 1 pound Italian sausage, 2 cloves garlic, 1 green pepper, 1/2 teaspoon salt, 1/4 teaspoon black pepper
Add crushed tomatoes, chicken broth, red pepper flakes, basil, and oregano, stirring to combine.
29 ounces crushed tomatoes, 2 cups chicken broth, 1/2 tablespoon dried basil, 1/2 teaspoon crushed red pepper flakes, 1/2 tablespoon dried oregano
Stir in rotini. Bring to a boil and then reduce heat and simmer for 10 to 15 minutes (or until the rotini just has a small bite to it), stirring occasionally. You should see consistent small bubbles.
8 ounces rotini
Stir in 1/2 cup of the mozzarella. Top with the rest of the cheese, the pepperoni, and the olives. Put it in the preheated oven and cook for 5 to 10 minutes or until the cheese has melted.
2 cups shredded mozzarella, pepperoni, sliced olives