Preheat the oven to 450°F.
In a large 9x13-inch baking dish, arrange the boneless skinless chicken breasts, grape tomatoes, and peeled garlic cloves.
Drizzle the chicken, tomatoes, and garlic with the extra virgin olive oil.
Sprinkle the Italian seasoning, salt, and ground black pepper evenly over the ingredients.
Using tongs, toss the chicken, tomatoes, and garlic until evenly coated with the oil and seasonings.
Arrange the chicken breasts in an even layer in the baking dish.
Create a well in the center of the baking dish.
Place the block of feta cheese in the center well, surrounded by the tomatoes, garlic, and chicken.
Transfer the baking dish to the preheated oven.
Bake uncovered for 30 minutes, or until the chicken is fully cooked and the tomatoes have softened.
Switch the oven to broil.
Broil for an additional 5 minutes, or until the feta cheese and top of the dish are lightly golden brown.
Remove the baking dish from the oven.
Cover loosely with foil and allow the dish to rest for 5 minutes.
Using a large spoon, gently stir the softened feta cheese, tomatoes, garlic, and pan juices together.
Press the tomatoes lightly with the spoon to release their juices and form a creamy tomato feta sauce.
Spoon the sauce over the chicken breasts.
Garnish with finely chopped fresh basil.
Serve warm with pasta, rice, salad, roasted vegetables, potatoes, couscous, quinoa, or crusty bread.