Put all ingredients except chicken in measuring cup, or deli container and shake or mix well to combine - set aside
Flatten chicken breasts to an even thickness, and place in a ziplock bag - add about ¾ of the marinade
Mush around to ensure chicken is well covered, seal the bag and refrigerate a couple hours
Remove from fridge at least 30 minutes before cooking
Grill on a very hot grill, turning often and brushing with reserved marinade once chicken is grilled on both sides - cook until chicken hits 165 degrees
Remove, brush again and use
SAUCE
¼ cup each mayo & non-fat Greek yogurt
Juice of ½ lemon
2 tablespoons garlic paste (or 2 large cloves minced)
2 tablespoons chopped curly parsley
Salt & pepper to taste
Combine all ingredients, and refrigerate until needed