Heat the olive oil in a large skillet or Dutch oven over medium heat.
Season the chicken breast with Italian seasoning, salt, and pepper, then add it to the skillet. Cook for 5-6 minutes per side, or until browned and cooked through.
Remove the chicken from the pan and set it aside to rest.
Add the minced garlic to the same pan and cook for 1 minute, stirring often.
Stir in the orzo and chicken broth. Bring to a gentle boil, then reduce the heat to a simmer.
Cover and cook for 8-10 minutes, stirring occasionally, until the orzo is tender and most of the liquid has been absorbed.
While the orzo cooks, slice the chicken.
Stir in the heavy cream, lemon juice, lemon zest, spinach, and parmesan cheese.
Add the sliced chicken back to the pan and cook for 2-3 minutes, until the spinach is wilted, the sauce is creamy, and the chicken is warmed through. Taste and adjust the salt, pepper, or lemon juice if needed before serving.
Brown the chicken first: Cooking the chicken whole before slicing helps keep it juicy and gives the dish better flavor from the browned bits left in the pan.
Stir the orzo while it cooks: Orzo can stick to the bottom of the pan, so stir it occasionally as it simmers.
Watch the liquid: If the orzo absorbs the broth too quickly before it is tender, add an extra splash of chicken broth and keep cooking until softened.
Add the lemon at the end: Stirring in the lemon juice and zest near the end keeps the flavor fresh and prevents it from cooking down too much.
Use gluten-free orzo carefully: Gluten-free orzo can soften faster than regular orzo, so check it early and cook just until tender.