Use a sharp knife to butterfly each chicken breast, creating a pocket for the marinade and ensuring even cooking.
In a mixing bowl, combine olive oil, lemon juice, minced garlic, salt, pepper, and the chopped herbs—basil, thyme, and oregano—whisking until well blended.
Place the chicken breasts in a resealable bag or shallow dish and pour the marinade over them, making sure each piece is evenly coated. Marinate in the fridge for at least 30 minutes, or up to 2 hours for more flavor.
Preheat your grill to medium-high heat, approximately 200°C (390°F), and clean and oil the grates to prevent sticking.
Remove the chicken from the marinade and place on the hot grill, skin-side down if applicable. Cook for about 6-8 minutes until golden brown and seared.
Flip the chicken using tongs and cook for another 6-8 minutes, or until the internal temperature reaches 75°C (165°F), ensuring the meat is cooked through but still juicy.
Transfer the cooked chicken to a plate and tent loosely with foil. Let it rest for 5 minutes to allow the juices to redistribute.
Slice the rested chicken against the grain, revealing juicy, herb-infused meat, and serve with a squeeze of fresh lemon or a drizzle of herb oil for extra brightness.