Using an oven proof skillet, heat 1Tbsp of oil to medium and cook the chicken for 2-3 minutes on each side until golden. Put on a plate. Now add the onion and garlic and cook for 2-3 minutes until soft. Remove the pan from the heat and add the tomatoes, Italian seasoning and remaining S&P. Return pan to medium heat and cook for about 2-3 minutes more. Now add the chicken back in to the sauce and coat well.