Preheat the oven to 375°F (190°C).
Pat the chicken dry and carefully slice a pocket into the side of each breast, careful not to cut all the way through. Stuff each with about 2 tablespoons of Boursin cheese. Season both sides with salt and pepper.
Heat a drizzle of olive oil in a skillet over medium-high heat. Sear the chicken for 2–3 minutes per side until golden—no need to cook it through, it’ll finish in the oven. Set aside after searing.
In a deep oven-safe dish or skillet, combine the orzo, broth, lemon zest, smashed garlic, thyme/oregano (if using), salt, and pepper.
Nestle the seared chicken on top and scatter cherry tomatoes around it. Drizzle with olive oil.
Bake uncovered for about 30 minutes, or until chicken is cooked through (165°F internal temp), orzo is tender, most of the broth has absorbed, and the tomatoes are blistered. If it looks dry near the end, stir in an extra ¼ cup of broth.
Let it rest for 5 minutes and then finish with fresh herbs and optional lemon juice or parmesan.