Begin by preheating your oven to 200°C (or 180°C for fan-forced ovens) to ensure it's ready for baking.

On a baking tray, spread out the panko breadcrumbs evenly and give them a light spray with oil. Place the tray in the preheated oven and bake for approximately 3 minutes, or until the breadcrumbs turn a light golden color. Once done, promptly transfer them into a bowl.

Now, prepare the chicken breasts by carefully cutting a pocket into each one. Take your cheese and fold each slice in half, then insert two pieces into the pocket of each chicken breast. Follow the same process with the ham, placing two slices into each pocket. Once filled, close the pocket of each chicken breast and secure it with two toothpicks. Before proceeding, season the chicken breasts with a sprinkle of salt and pepper.

In a bowl, whisk together the egg and flour until well combined. Next, dip each stuffed chicken breast into the egg mixture, ensuring it's evenly coated, then coat it with the prepared panko breadcrumbs. Once coated, transfer the breaded chicken breasts onto a baking tray and give them a light spray with oil for a golden finish.

Place the tray of prepared chicken breasts into the preheated oven and bake for approximately 25 to 30 minutes, or until they turn a beautiful golden brown and are just cooked through. Once done, carefully remove the toothpicks from each chicken breast. Serve your delicious stuffed chicken alongside your favorite sauce and a selection of vegetables.