Pat the chicken breasts dry and place them in a container with a lid.
Pour in 3 Tablespoons of olive oil, all of the balsamic vinegar and 1 teaspoon of the minced garlic. You can also add Greek seasoning, if desired.
Cover and refrigerate overnight.
Allow chicken to sit out for about 10 minutes before proceeding with cooking.
Place 2 Tablespoons of olive oil in a skillet over medium heat.
Add the chicken breasts to the skillet and cook through, about 8 minutes per side, until an inserted thermometer reads 165F.
While the chicken is cooking, prepare your bruschetta topping.
In a medium-sized bowl, combine the tomato, onion, basil, salt, lemon juice and remaining garlic and olive oil. Stir to combine, then taste and adjust, as desired.
When the chicken is done cooking, remove from the skillet to your serving plate and divide the bruschetta mixture overtop.