01 - 
                Set your oven to 375°F (190°C).
              
              
              
                02 - 
                Heat olive oil in a skillet over medium heat.
              
              
              
                03 - 
                Sauté the chopped onion and garlic until the onion becomes soft and translucent.
              
              
              
                04 - 
                Add the chopped spinach and cook until wilted. Remove from heat and allow it to cool slightly.
              
              
              
                05 - 
                In a bowl, combine the spinach mixture with crumbled feta cheese and chopped sun-dried tomatoes. Season with salt and black pepper to taste.
              
              
              
                06 - 
                Butterfly each chicken breast and gently pound them to an even thickness.
              
              
              
                07 - 
                Spoon the spinach and feta filling onto the center of each chicken breast. Roll them up tightly and secure with toothpicks.
              
              
              
                08 - 
                Place the stuffed chicken breasts in a baking dish, seam side down. Bake for 25–30 minutes, or until the chicken is fully cooked and the juices run clear.
              
              
              
                09 - 
                Remove the toothpicks before serving. Enjoy with a side of rice, roasted vegetables, or a fresh salad.