Start by making the marinade. Whisk together the olive oil, balsamic vinegar, honey, garlic, Italian seasoning, salt, pepper, and crushed red pepper in a small bowl. You can also put the ingredients into a mason jar, put the lid on tightly, and vigorously shake.
If you need to pound out the chicken breasts, so they are of even thickness. Place the chicken in a bowl, dish, or plastic bag and pour the marinade over the top. Make sure to cover the chicken.
Place chicken into the refrigerator and marinate for at least one hour or preferably overnight.
When you’re ready to cook the chicken, prepare the grill. Set the grill temperature to medium-high heat.
After the grill is hot, remove the chicken from the marinade and place it directly onto the hot grill. Discard the marinade.
Close the grill and grill the chicken for 5-7 minutes, and then using tongs, flip to the other side and grill for another 5-7 minutes or until the internal temperature reaches 165º. Remember, don’t push down on the chicken as it cooks.
Remove the chicken from the grill and place it on a plate and cover it with foil. Let the chicken rest for 3 – 5 minutes before slicing and serving.