Note: size the burgers according to the size of your buns! You can make large burgers or smaller sliders. Also, you only need as many mozzarella cubes as you have burgers.
Combine the tomatoes, garlic, basil, olive oil, salt and pepper in a bowl. Let it sit at room temperature while you prepare the burgers.
Preheat your grill to high.
Place the chicken in a bowl and mix in the fresh basil, dried basil, garlic powder, salt, pepper and pepper flakes until combined. Divide the chicken into 6 or 8 equal pieces (or honestly, pieces that match the size of buns you have!). Form the pieces into a patty and press a cube of the mozzarella into the center. Form the patty around the mozzarella so it’s completely covered. Repeat with remaining patties and cheese cubes.
Place the burgers on the grill and cook for 5 minutes, then flip and cook for 3 to 5 minutes more. You want to make sure the internal temperature is 165 degrees F - and make sure you’re taking the temp of the meat and not the cheese in the center! Once the burger is almost done, place a slice of mozzarella on top and let it melt for 1 minute or so.
Once the burger is done, place it on the bun and cover it with the tomato bruschetta mixture. Drizzle with balsamic glaze! Serve with the extra tomatoes on the side.
P.S. this is slightly messy to eat because the tomatoes do start to fall out of the sides of the sandwich - but it’s so good!