the iron plate for cooking on is a girdle, not a griddle.
What a highlander carried would depend on where he was from.
with his plaid, dirk and sghian dhu he has everything he needs to provide shelter for himself. the sporran wold have held a few "possibles". tinderbox, snares possibly needles and thread, whetstone, etc.
food would have been in a separate sack slung on the back.