1. Heat olive oil in a large deep skillet or Dutch oven over medium heat.

2. Add Italian sausage and cook until browned, breaking it up as it cooks. Drain excess fat.

3. Add diced onion and bell pepper; sauté for 4–5 minutes until softened.

4. Stir in garlic, Italian seasoning, and crushed red pepper flakes. Cook for 30 seconds.

5. Add marinara or pizza sauce and chicken broth. Stir to combine.

6. Add rotini pasta and stir well. Bring to a gentle boil.

7. Reduce heat to medium-low, cover, and simmer for 12–15 minutes, stirring occasionally, until pasta is tender.

8. Mix in black olives, pepperoni, and half of the mozzarella and Parmesan cheeses.

9. Stir until cheese is melted, then sprinkle remaining cheeses on top.

10. Cover or broil for 2–3 minutes until cheese on top is melted and bubbly.

11. Garnish with chopped basil or parsley and serve hot.