Prep the ingredients: Dice the chicken breasts into uniform 1-inch bite-sized pieces. Mince the garlic finely. Roughly chop the sun-dried tomatoes if they're in large pieces. Measure out your orzo and have all ingredients ready before you start cooking.
Sear the chicken: Heat 2 tablespoons of olive oil in a large, deep skillet over medium-high heat until shimmering. Add the chicken pieces in a single layer (work in batches if needed). Season generously with salt and pepper. Let cook undisturbed for 2-3 minutes to develop a golden-brown crust, then flip and cook another 2-3 minutes until golden and just cooked through. Remove chicken to a plate and set aside.
Build the flavor base: In the same skillet, reduce heat to medium. Add the minced garlic and sauté for about 1 minute, stirring constantly until fragrant (watch carefully so it doesn't burn). Add the chopped sun-dried tomatoes and stir for another minute to warm them through.
Cook the orzo: Pour in the chicken broth and increase heat to bring it to a rolling boil. Once boiling, stir in the orzo pasta, making sure all grains are submerged. Reduce heat to low, cover the skillet with a lid, and simmer gently for 10-12 minutes, stirring once or twice, until the orzo is tender and has absorbed most of the liquid. The orzo should be al dente with just a slight bite.
Add cream and spinach: Once the orzo is cooked, reduce heat to medium-low and pour in the heavy cream. Stir gently to incorporate throughout the dish. Add the fresh spinach and stir until it wilts down into the sauce, about 1-2 minutes.
Finish the dish: Return the reserved chicken (along with any accumulated juices) to the skillet. Stir everything together gently. Let simmer uncovered for 2-3 minutes until the sauce reaches your desired consistency—it should be creamy and coat the orzo nicely, not soupy. If too thick, add a splash more broth; if too thin, simmer a minute longer. Taste and adjust seasoning with additional salt and pepper if needed.
Rest and serve: Remove from heat and let the dish rest for 3-4 minutes. This allows the orzo to finish absorbing liquid and the flavors to meld. If using, stir in freshly grated Parmesan cheese and garnish with fresh basil or parsley. Serve immediately while hot and creamy.