• Preheat oven to 375°F.

Prepare the Filling

• Heat olive oil in a cast iron pan or oven-proof skillet over medium low heat. Add shallot and garlic and cook stirring until softened, about 4 minutes. Add spinach and cook until fully wilted. Transfer mixture to a small bowl and give the pan a quick rinse (you'll use it for cooking the chicken).
• Combine feta cheese and nutmeg in a medium mixing bowl. Add the spinach mixture and stir until well combined.

Prepare the Chicken

• Using a small, sharp knife, carefully cut pockets into the side of each chicken breast.
• Sprinkle the salt, pepper and paprika over both sides of the chicken breasts. Rub the seasoning in with your hands.
• Divide up the filling and spoon it into the pocket of each breast, packing it in as much as possible as you go.

Cook the chicken

• Heat olive oil over medium in the same pan you used for the spinach. Add in the chicken and cook until just browned on each side (about 4 minutes per side).
• Place the chicken in the oven and cook for 15-20 minutes (or until it reaches an internal temperature of 165°F).
• Let chicken rest for 5 minutes before serving.