Follow these steps to prepare your Stuffed Chicken Breast with Red Pepper, Spinach, and Mozzarella:

1. Preheat Oven: Preheat your oven to 375°F (190°C). This ensures the chicken will cook evenly.
2. Sauté Vegetables: In a skillet, heat the olive oil over medium heat. Add the garlic, diced red bell pepper, and chopped spinach. Sauté until the spinach is wilted and the pepper is tender, about 3-5 minutes. Season with Italian seasoning, salt, and pepper.
3. Prepare Chicken: While the veggies are cooking, use a sharp knife to create a pocket in each chicken breast without cutting all the way through.
4. Stuff Chicken: Fill each chicken breast pocket with the sautéed vegetables and a generous amount of mozzarella cheese. Secure the openings with toothpicks or kitchen twine to hold the filling inside.
5. Brown Chicken: In the same skillet, add a little more olive oil if needed, and place the stuffed chicken breasts. Sear them for about 2-3 minutes on each side, or until golden brown.
6. Bake Chicken: Transfer the seared chicken breasts to a baking dish. Bake in the preheated oven for 25-30 minutes, or until the chicken is cooked through and the juices run clear.
7. Rest Before Serving: Remove the stuffed chicken from the oven and let it rest for 5 minutes. This allows the juices to redistribute, keeping the chicken juicy.

These steps provide a clear path to crafting your delicious Stuffed Chicken Breast with Red Pepper, Spinach, and Mozzarella.