Slice chicken breasts in half lengthwise so that they're thinner and cook more quickly. Season with salt and pepper.
In a large skillet or cast iron, heat the olive oil over medium-high heat. Sear the chicken breasts for 1-2 minutes on each side. Remove chicken from the pan and set aside.
Melt the butter in the pan, then sauté the shallot and garlic for 2-3 minutes.
To the same pan, add in the dry orzo and thyme and stir frequently for 1-2 minutes.
Stir in the chicken broth and bring to a simmer. Reduce heat to low.
Return the chicken breasts back to the pan and push them down into the broth. Cover and let simmer for 10-15 minutes (stirring occasionally so that the orzo doesn't stick to the bottom) until both the orzo and chicken are fully cooked and most of the liquid is absorbed.
Turn off the heat. Remove the chicken breasts to a cutting board. Stir in the heavy cream, parmesan, spinach, basil, lemon zest, and lemon juice. Taste and add more salt and pepper if needed.
Slice the chicken breasts and return to the orzo. Serve with grated parmesan.
