1. Preheat oven to 350°.
2. Combine first 4 ingredients in a small bowl. Cut a horizontal slit through thickest portion of each chicken breast half to form a pocket. Stuff cheese mixture evenly into pockets.
3. Place flour in a shallow dish. Combine milk and egg in a shallow dish, stirring well with a whisk. Place panko in a shallow dish. Working with 1 chicken breast half at a time, dredge chicken in flour, then dip in egg mixture; dredge in panko. Repeat procedure with remaining chicken, flour, egg mixture, and panko.
4. Heat a large ovenproof skillet over medium-high heat. Add 1 tablespoon butter to pan; swirl until butter melts. Arrange chicken in pan; cook 4 minutes or until browned. Turn chicken over; place skillet in oven. Bake at 350° for 20 minutes or until done.
5. While chicken bakes, combine remaining 1 1/2 teaspoons butter, bell peppers, water, Worcestershire, and garlic in a small saucepan over medium heat. Bring to a simmer; cook until butter melts. Remove from heat, and stir in hot sauce. Serve sauce with chicken.