Heat the extra-virgin olive oil and garlic in a large skillet over medium-low heat.
Add the tomatoes and crush them gently with a wooden spoon. Season with oregano, cover with a lid, and cook for 10 minutes over low heat, stirring often.
Add the chicken breast slices to the skillet and cook for 5 minutes (or more depending on the thickness of the meat).
Turn the chicken halfway through the cooking time. Once ready, top the chicken with mozzarella slices and cover the pan with a lid until the cheese has melted.
Remove the pan from the heat, discard the garlic, season your chicken pizzaiola with more oregano and extra-virgin olive oil if you like, and serve.
