Cut the chicken breasts in half like a butterfly, horizontally. Place the chicken flat on a cutting board and cover with baking paper. Use a rolling pin to pound and flatten the pieces.
Season the chicken with salt and pepper on both sides.
In a separate bowl, whisk together the egg and water.
To bread the chicken, you first pass them through the flour and shake it gently to remove the excess. Then pass through the egg and let the excess drip. Finish with the panko.
In a pot or pan, preheat the oil over medium heat. If you have an oil thermometer, it should mark 180°C/350°F.
Fry a piece at a time for 3-4 minutes or until very golden. When you remove them from the oil, place them on a baking tray with a cooling rack on top.
Slice the chicken for serving.