Mix up all the ingredients for the marinade. Butterfly the chicken breasts by putting your hand on top of the breast and then carefully cutting through sideways but stopping just before you slice the breast in half. Put the breasts in the marinade. Coat and leave to sit for at least 30 minutes. You can even do this the day before.
Chop up all the salsa ingredients. Put in a bowl and add the vinegar, oil, salt and pepper. Mix together and leave to sit until the rest of the meal is ready.
Brush a griddle pan with oil and place the chicken breasts on the griddle. Cook on a high heat for about 4 minutes on each side, depending on how thick the meat is.
Serve the chicken with the salsa. Drizzle a bit of extra mango vinegar over the top. I also served it with some basmati rice with fresh coriander and lemon juice stirred through.
Nutritional information is approximate and a guideline only.