Step 1: Preheat the Oven

Preheat the oven to 375°F (190°C). A fully preheated oven ensures even cooking and helps keep the chicken moist.

Step 2: Prepare the Chicken

Pat the chicken breasts dry with a paper towel. This helps the seasoning adhere properly and prevents excess moisture during baking. Using a sharp knife, carefully slice along the side of each chicken breast to create a pocket, making sure not to cut all the way through.

Step 3: Season the Chicken

In a small bowl, mix the olive oil, garlic powder, Italian seasoning, salt, and pepper. Brush this mixture evenly over the chicken, making sure to coat both sides.

Step 4: Prepare the Filling

Evenly distribute the roasted red peppers, fresh spinach, and shredded mozzarella cheese among the chicken breasts. Carefully stuff the ingredients into each pocket, pressing them in gently. If needed, secure the openings with toothpicks to prevent the filling from spilling out while cooking.

Step 5: Arrange in a Baking Dish

Grease a baking dish lightly with olive oil. Place the stuffed chicken breasts inside, ensuring there is enough space between each piece for proper air circulation. This helps them cook evenly and develop a nice golden exterior.

Step 6: Bake the Chicken

Place the baking dish in the preheated oven and bake for 25-30 minutes. To check for doneness, insert a meat thermometer into the thickest part of the chicken. The internal temperature should reach 165°F (75°C).

Step 7: Rest and Serve

Once cooked, remove the chicken from the oven and let it rest for about 5 minutes before serving. This step allows the juices to redistribute, keeping the meat tender and flavorful. Carefully remove any toothpicks before plating.