Add the oil, butter, tomatoes, olives, capers, oregano, garlic, and orzo to a pot over medium-high heat. Once the butter melts, cook for 2 minutes, stirring often.
Add in the wine and let it bubble for about 30 seconds, then stir in the chicken broth. Let it come to a gentle boil, then continue cooking for 10 minutes, uncovered, stirring fairly often ensuring the orzo doesn't cement to the pot. You will probably need to turn the heat down (to medium or even medium-low). It should simmer vs. boil like crazy, and you don't want the liquid to reduce too much before the orzo is cooked.
Stir in the chicken, spinach, and feta.
Take the pot off the heat, and cover it for 3-5 minutes or until the spinach has wilted, the cheese has melted a bit, and more of the broth has been absorbed. Season with salt & pepper if needed and serve immediately.
