01 - Preheat oven to 400°F. Lightly grease a baking dish with a small amount of olive oil.
02 - In a medium mixing bowl, combine ricotta cheese, chopped spinach, grated Parmesan, minced garlic, nutmeg, salt, and black pepper. Stir until the mixture is uniform.
03 - Pat the chicken thighs dry with paper towels. Arrange thighs smooth side down on a cutting board. Evenly sprinkle with salt, black pepper, and Italian seasoning.
04 - Spoon a generous portion of the ricotta-spinach filling onto each chicken thigh. Roll each thigh tightly around the filling and place seam-side down in the prepared baking dish.
05 - Drizzle the stuffed chicken thighs with olive oil, then evenly sprinkle shredded mozzarella cheese on top.
06 - Cover the baking dish with aluminum foil and bake for 20 minutes.
07 - Remove the foil and continue baking for another 15 minutes, until the chicken is thoroughly cooked (internal temperature reaches 165°F) and the cheese is golden.
08 - Allow the stuffed chicken thighs to rest for 5 minutes before serving.