02In a large skillet, heat olive oil over medium-high heat. Sauté onions until translucent and tender, about 5 minutes. Stir in roasted red peppers and garlic. Add spinach, cover and cook for about 3 minutes until spinach is soft and wilted. Remove from heat. Let mixture cool slightly, stir in mozzarella and parmesan.
03Beginning in the center of the thicker end of the chicken breast, insert a small knife horizontally, stopping about 1 inch from the opposite end. Open incision to create a 1-inch wide pocket and pack about 1/4 of the filling mixture into each chicken breast.
04Season chicken with Italian seasoning blend and place in 13 x 2-inch baking dish. Pour broth over chicken. Cover loosely with foil and bake for 40 minutes; keep warm until served.