01 - Preheat oven to 350°F (180°C).
02 - Place chicken breasts between two sheets of plastic wrap and pound to about 1/2-inch thickness using a meat mallet.
03 - Season both sides of the chicken breasts evenly with salt, pepper, garlic powder, and paprika.
04 - Lay 1 slice of ham and 1 slice of Swiss cheese on each seasoned chicken breast.
05 - Roll each breast tightly, tucking in the ends. Secure the seam with toothpicks to hold the filling in place.
06 - Arrange three shallow bowls: place flour in the first, beat eggs with milk in the second, and combine panko breadcrumbs with grated Parmesan in the third.
07 - Coat each chicken roll in flour, then dip into the egg mixture, and finally press thoroughly into the panko-Parmesan blend until evenly covered.
08 - Heat vegetable oil in a large oven-safe skillet over medium-high heat. Sear each chicken roll until golden brown on all sides, about 2 to 3 minutes per side.
09 - Transfer the skillet to the oven (or place chicken rolls on a baking sheet) and bake for 20 minutes until the chicken is cooked through and the cheese is fully melted.
10 - Remove toothpicks from the chicken rolls. Slice each roll into medallions and serve hot.