Season the chicken. Pat the chicken dry and season with 1 teaspoon kosher salt and 1/2 teaspoon black pepper.
If you like a little heat, add a pinch of red pepper flakes.
Sear the chicken. Heat 1 tablespoon olive oil in a large deep skillet or Dutch oven over medium-high heat. Add the chicken in a single layer and cook until lightly browned and just cooked through, about 4–6 minutes. Transfer to a plate and keep warm.
Soften the aromatics. Reduce heat to medium.
Add remaining 1 tablespoon olive oil and the butter. Stir in the onion with a pinch of salt. Cook until translucent, 3–4 minutes, then add garlic and cook 30 seconds until fragrant.
Toast the orzo. Add the dry orzo to the pan.
Stir to coat in the butter and oil, toasting for 1–2 minutes. This adds a nutty flavor and keeps the grains from clumping.
Add the broth. Pour in the chicken broth and bring to a gentle simmer. Scrape up any browned bits from the bottom; that’s pure flavor.
Simmer until tender. Cook, stirring occasionally, for 8–10 minutes, or until the orzo is just tender and most of the liquid is absorbed.
If it looks dry before it’s done, add a splash of hot water or more broth.
Make it creamy. Stir in the cream, Parmesan, lemon zest, and 3 tablespoons lemon juice. Return the chicken and any juices to the pan. Simmer 2–3 minutes more, stirring, until the sauce is silky and coats the orzo.
Add greens and herbs. Fold in the spinach (or kale) until wilted.
Stir in the fresh parsley or basil. Taste and adjust: add more lemon for brightness, salt for balance, or pepper for warmth.
Finish and serve. The texture should be loose and creamy, like a thick risotto. If it tightens too much, splash in a little warm water or broth.
Serve hot with extra Parmesan, a drizzle of olive oil, and lemon wedges.