Heat a large (12”) skillet over medium-high heat. Add olive oil and butter. Cook until the butter melts and begins to foam. Add the chicken strips, in batches to avoid overcrowding, and cook until lightly golden on both sides. Remove the chicken and set aside.
Reduce the heat to medium and add the onion. Cook until softened, about 4-5 minutes. Then stir in the garlic, paprika, and red pepper flakes (if using). Cook just until fragrant.
Stir in the orzo and let it toast for about a minute. Add the chicken broth, salt, pepper, lemon zest, and lemon juice. Return the chicken and any juices to the skillet and stir, scraping up any browned bits from the bottom of the pan.
Cover and simmer, stirring occasionally, over medium-low heat until the orzo is tender and most of the liquid is absorbed, about 10 minutes.
Remove the lid and stir in the parmesan and heavy cream. Fold in the spinach and let it wilt gently into the pasta. Taste and adjust seasoning. Finish with fresh parsley. Allow to rest for about 5 minutes to thicken up.
Serve with green salad, roasted asparagus or broccoli, and garlic bread.