Preheat your oven to 375°F (190°C).
In a large mixing bowl, combine the shredded chicken, pizza sauce, mozzarella cheese, cheddar cheese, Italian seasoning, pepperoni, bell peppers, and black olives (if using). Mix well until all ingredients are evenly coated.
Take a tortilla and spoon about 1/4 cup of the chicken mixture onto the center. Roll the tortilla tightly and place it seam-side down in a greased 9x13 inch baking dish. Repeat with the remaining tortillas and filling.
Once all the enchiladas are in the baking dish, pour any remaining pizza sauce over the top and sprinkle with Parmesan cheese.
Cover the dish with aluminum foil and bake for 20 minutes. Remove the foil and bake for an additional 10-15 minutes, or until the cheese is bubbly and golden.
Remove from the oven and let cool for a few minutes. Garnish with fresh basil or parsley if desired before serving.