Keep 10 pepperoni slices aside and cut the remaining slices in half.
Heat olive oil in a large deep pan over high heat then add onion, mushroom, bell pepper and halved pepperoni and sauté for 5 to 7 minutes until vegetables start to be golden.
Add the ready pizza sauce and stir well to combine.
Add tomato puree, crushed tomato and chicken broth and keep to simmer for few minutes.
Add in the dry pasta and fresh oregano, season with salt and pepper and stir well.
Cover the pan and reduce heat to medium-low and let cook for 15 minutes until pasta is al dente.
Uncover and keep cook for a further 4 to 5 minutes until mixture thickens and pasta is tender and cooked perfectly.
Preheat grill on high. Sprinkle the pasta with mozzarella cheese and top it with reserved pepperoni slices.
Grill for 2 to 3 minutes until cheese is golden. Garnish with fresh basil leaves and serve warm.