1. Preheat the oven to 350 degrees F. Coat a baking sheet with cooking spray.
2. Warm a large nonstick skillet over medium heat. Add the spinach and cook, tossing, 3 minutes or until bright green and wilted. Add the garlic and nutmeg and cook, tossing, 2 minutes. Transfer to a bowl; remove skillet from heat and wipe with a paper towel.
3. Butterfly each chicken breast and open as you would a book; pound to an even 1/4-inch thickness.
4. Squeeze some of the liquid from spinach and toss with the feta and dill. Place a quarter of the mixture along the center of each breast; roll and secure with toothpicks.
5. In the skillet, heat 1 tablespoon of the oil over medium-high heat. Add stuffed chicken and cook 4 to 5 minutes or until the bottoms are golden. Turn and cook another 5 minutes.
6. Transfer chicken to the prepared baking sheet; bake in the center of oven 15 minutes or until cooked through.
7. Bring a pot of lightly salted water to a boil; add the orzo and cook according to package directions. Drain and toss with remaining oil and the lemon zest and lemon juice, Parmesan and parsley. Serve with chicken.