2Heat a deep pan or pot over medium-high heat with a drizzle of olive oil.
3Add the diced onion to the pan.
4Stir in the tomato paste, Italian seasoning, red pepper flake, salt, black pepper, and minced garlic. Keep moving for one minute until the tomato paste darkens.
5Stir in the dried orzo and toast for one minute.
6Add the marinara and chicken broth. Mix everything together.
7Simmer uncovered for ten minutes until the orzo is tender. Stir occasionally to prevent sticking.
8Turn off the heat, cover the pan with shredded mozzarella cheese, and add pepperoni slices on top.
9Melt the cheese by either covering the pan with a lid or placing the oven-safe pan under a broiler for two to three minutes.