Wash the chicken breasts and set aside.
Place a small frying pan on a stove set at medium-high heat. Add 1 tablespoon of olive oil, chopped garlic, cherry tomatoes, and lastly spinach. Allow it to cook until the spinach becomes soft.
Now make deep cuts in the chicken breasts. Stuff the deep cuts with pepper, salt, and optionally tomato basil sauce. Add to that cooked spinach and a tablespoon of cheese. Fasten the cuts with toothpicks.
Without cooking the chicken, allow it to brown in the small frying pan. Now transfer the chicken to a deep tray and add the remainder of the olive oil.
Spread the sauce on the chicken evenly. Cover it with a foil.
Preheat your oven to 375F and allow it to cook until it is done.
Lastly, sprinkle the rest of the cheese on the chicken. Place it back in the oven and allow it to sit for a couple of minutes until the cheese is completely melted.
Remove and allow to cool a bit.
Serve and enjoy.