Slice the chicken breasts in half lengthwise ("butterfly") so they’re thinner.
Sprinkle chicken breast with some Kosher salt.
Mix up Greek yogurt, minced garlic, salt and oregano in a small bowl.
Grate in some of the rind from the lemon and then cut the lemon in half and squeeze in all the juice. Stir again.
Place chicken breasts in large ziplock bag and pour marinade over. Seal the bag and turn to coat.
Marinade for 6 hours or overnight in the fridge.
When ready to cook the chicken, take the chicken out of the bag. Discard the leftover marinade.
BBQ or grill the chicken breasts on medium heat for approximately 10 minutes per side, turning once until the internal temperature is 165 degrees F on an instant read thermometer. Serve warm.