Place chicken breast pieces in a medium bowl, sprinkle with salt and pepper and mix to coat.
Heat 1 tablespoon olive oil in a heavy-bottomed skillet or a wide dutch oven.
Add chicken in one even layer and cook undisturbed on medium heat for 5 minutes, then flip and cook on the other side for 3-5 minutes, until golden brown and cooked through.
Remove cooked chicken from the now empty skillet and transfer to a plate. Set aside. If your skillet has lots of brown bits stuck to the bottom - that's good. It's flavor!
To the now empty skillet add 1 tablespoon of olive oil and chopped onion and garlic. Cook, stirring for 2-3 minutes, then add dry orzo and cook stirring for 1 more minute to toast.
Pour in 1 cup of broth and stir with a wooden spoon to deglaze the pan (loosen all the brown bits).
Add remaining broth, light cream and juice from ½ lemon. Bring to a boil, then reduce to a simmer and cook, stirring from time to time for 10 minutes.
Once the orzo absorbs most of the liquid, add the cooked chicken, pesto and parmesan cheese. Stir to incorporate.
Add baby spinach and stir it in until wilted. If the orzo is very thick, add another splash of broth or water.
Serve with freshly grated parmesan garnished with fresh basil leaves.