Pat the chicken dry with paper towels. Season both sides with salt, black pepper, paprika, and garlic powder.
Heat 3 tablespoons of olive oil in a large skillet over medium-high heat. Add the chicken and sear for 4 to 5 minutes per side, until golden brown. Transfer the chicken to a plate. It does not need to be fully cooked yet.
Reduce the heat to medium. Add the diced onion to the same skillet and cook for 2 to 3 minutes, until softened. Add the garlic and cook for about 30 seconds, just until fragrant.
Add the orzo to the skillet and stir it with the onion, garlic, and any flavor left in the pan for about 1 minute.
Pour in the chicken broth and scrape up the browned bits from the bottom of the pan. Return the chicken to the skillet, cover, and simmer for 10 to 12 minutes, stirring once or twice so the orzo cooks evenly and does not stick.
When the orzo is tender, reduce the heat to low. Stir in the room-temperature heavy cream, Parmesan cheese, Italian seasoning, and butter. Let the sauce warm gently until creamy and smooth.
Remove the skillet from the heat and stir in the lemon juice. Let the creamy chicken orzo rest for 3 to 5 minutes before serving.
Serve warm with fresh parsley and extra Parmesan.