Follow the steps in order for the best result.
Carefully slice a pocket into each chicken breast, creating space for the filling.
Envelop each cheese cube with a slice of ham, then gently insert the ham-wrapped cheese into the pocket you created in the chicken breast. Use toothpicks to secure the opening, ensuring the filling stays inside during cooking.
In separate shallow dishes, season both the panko breadcrumbs and the milk generously with salt and pepper to enhance the flavor of the dish.
Dip each chicken breast into the milk, ensuring it's fully coated. Then, transfer the chicken to the panko breadcrumbs, pressing gently to coat thoroughly and evenly.
Place the breaded chicken breasts on a baking sheet and bake in a preheated oven at 350 degrees Fahrenheit for approximately 45 minutes, or until the chicken is cooked through and the juices run clear.