Preheat oven to 500 degrees
For the garlic oil:
Mix all ingredients thoroughly – divide in half.
For the chicken:
Toss tomatoes with half the garlic oil – let rest 10 minutes.
Toss chicken breasts with remainder of garlic oil, making sure to coat completely – let rest 10 minutes.
Place 1 cup of the Parmesan cheese in shallow dish. Dip one side of chicken and sides in cheese, making sure to coat evenly. Place on baking sheet, cheese side up. Scatter tomatoes around chicken in pan.
Roast until chicken is done, about 10-12 minutes. Remove chicken from oven and top with the sliced mozzarella. Return oven just until cheese melts, 1-2 minutes.
Arrange chicken and tomatoes on serving platter and sprinkle with rest of Parmesan.