Pat the chicken breasts dry and season both sides with salt and pepper.
Heat the olive oil in a large pan over medium heat. Add the chicken and sear for about 4 minutes per side, or until golden and cooked through (internal temp should reach 165°F). Remove from the pan and set aside, loosely covered with foil to keep warm.
Add the butter to the same pan. Once melted, add the garlic and red pepper flakes. Sauté for about 1 minute, just until fragrant.
Stir in the tomato paste and cook for 2–3 minutes, stirring often, until it darkens in colour slightly.
Add the chopped tomato and cook for another 2–3 minutes, until slightly softened and a little bit jammy.
Stir in the orzo so it’s well coated in the tomato mixture, then pour in the chicken broth.
Bring to a bubble, then reduce heat to medium-low. Simmer, stirring occasionally, until the orzo is tender and most of the liquid is absorbed. If needed, add a splash more broth to finish cooking the orzo. Taste and adjust the seasoning if needed.
Slice the chicken and serve over the orzo. Top with grated pecorino and some fresh Italian parsley or basil!