Prepare the Chicken: Preheat your oven to 200°C (180°C fan). Place the chicken breasts on a cutting board, cover with cling film, and use a rolling pin or meat mallet to gently pound them to a uniform thickness of about 1.5cm (just over half an inch). This is crucial for even cooking. Pat them completely dry with a paper towel.

Set Up Your Dredging Stations: You'll need three shallow dishes. In the first, mix the plain flour with the salt and black pepper. In the second, whisk the eggs and Dijon mustard together until smooth. In the third dish, combine the panko breadcrumbs, grated cheddar, smoked paprika, garlic powder, and onion powder. Mix well with your fingers to ensure everything is evenly distributed.

Coat the Chicken: Working with one chicken breast at a time, first dredge it in the seasoned flour, shaking off any excess. Next, dip it into the egg mixture, allowing any extra to drip off. Finally, press it firmly into the cheddar and breadcrumb mixture on both sides. I find that really pressing the coating on helps it stick during cooking. Place the coated chicken on a clean plate.

Sear for Colour: Heat the olive oil and butter in a large, oven-safe frying pan or skillet over a medium-high heat. Once the butter is melted and foaming, carefully place the coated chicken breasts in the pan. Be sure not to overcrowd it; cook in two batches if necessary.

Develop the Crust: Fry for 2-3 minutes on each side, until the coating is a deep golden brown and crisp. This step is purely to build the crust, not to cook the chicken through.

Finish in the Oven: Transfer the entire oven-safe skillet to the preheated oven. If your pan isn't oven-safe, move the seared chicken to a baking tray. Bake for 12-15 minutes, or until the chicken is cooked through and the cheese is completely melted and bubbling. The internal temperature should reach 74°C (165°F) on a meat thermometer.

Rest Before Serving: Remove the chicken from the oven and let it rest in the pan or on the tray for at least 5 minutes before serving. This allows the juices to redistribute, ensuring a tender, moist result.