Preheat the Oven:
Preheat your oven to 400°F (200°C). Lightly grease a baking dish.
Prepare the Filling:
In a bowl, mix ricotta, chopped spinach, Parmesan, garlic, Italian seasoning, salt, pepper, and a pinch of red pepper flakes (if using).
Stuff the Chicken:
Slice a pocket into the side of each chicken breast. Spoon the ricotta-spinach mixture into each pocket. Secure with toothpicks if needed.
Sear the Chicken (Optional for more flavor):
Heat olive oil in a skillet over medium-high heat. Sear chicken for 2–3 minutes per side to get a golden crust. Then transfer to the prepared baking dish.
Bake:
Top each stuffed breast with shredded mozzarella. Bake for 25–30 minutes, or until chicken is cooked through (165°F internal temp).
Serve:
Let rest for 5 minutes before serving. Serve with roasted vegetables, a side salad, or over zucchini noodles for a low-carb option.