Put the lemon juice into a medium bowl. Add the garlic, salt and pepper and whisk until the salt dissolves.
Add the olive oil, red pepper and herbs. Whisk to combine.
Put the chicken breasts in a baking dish and pour the marinade over. Turn the pieces to coat on both sides. Marinate at room temperature 15-30 minutes before cooking.
To marinate the chicken up to 6 hours ahead, place the chicken in a bowl or heavy-duty resealable plastic bag. Pour the marinade over and flip the chicken with tongs, or squish the bag with your hands to distribute the liquid evenly.
