Pat the chicken dry using paper towels. Use a sharp knife to cut each chicken breast horizontally into two halves to create thinner pieces. prep

Place the chicken halves between two sheets of plastic wrap. Use a meat mallet or rolling pin to pound the chicken into even, thin pieces. Be careful not to tear the chicken. prep

Lay one slice of ham and a handful of shredded Swiss cheese on top of each chicken piece. Roll the chicken tightly, tucking in the sides. Place each roll on a new piece of plastic wrap. assemble

Wrap the chicken rolls tightly in the plastic wrap, pinching the ends to create a tootsie-roll shape. Twist the ends to secure the rolls. Refrigerate for at least 30 minutes, or up to 1 day. prep

Preheat the oven to 400°F (200°C). Remove the chicken rolls from the refrigerator, unwrap, and season with salt and pepper. prep

In a food processor, pulse the cornflakes until they become fine crumbs. Transfer the crumbs to a shallow dish. In a separate dish, melt the butter. prep

Dip each chicken roll in the melted butter, then coat evenly in the cornflake crumbs. Press gently to help the crumbs adhere. Arrange the coated rolls on a lightly greased baking sheet. assemble

Bake on the center rack for 30 minutes, or until the chicken reaches an internal temperature of 160°F (71°C). Be sure to check the chicken, not the filling. bake

In a small bowl, mix together the mayonnaise and mustard. Taste and adjust mustard to your preference. finish

Serve the crispy chicken rolls with the mustard mayo sauce on the side for dipping. finish