Place chicken between 2 sheets cling film (plastic wrap). Lightly pound with a meat mallet or rolling pin to tenderise.
Heat half of the olive oil in a large frying pan over medium heat. Add the chicken and cook until browned all over (approximately 2 minutes on each side). Transfer the chicken to a plate and set aside.
Heat the remaining olive oil. Add the garlic and soften without browning for 2 minutes, then add the capers and tomatoes. Season well with salt and pepper. Cook for 5 minutes or until the tomatoes have reduced.
Return the chicken breast fillets to the frying pan and spoon pizzaiola sauce over the top. Cook the chicken for 3 minutes on one side. Turn the breast fillets. Add the olives, mozzarella and sprinkle oregano over the top. Cook for a further 3 minutes or until cooked through.
To serve, sprinkle the basil leaves over the Chicken alla pizzaiola – buon appetito.