Inkpujin's soul; final hint

'A rocky patch, far to the west, underneath the clue will tell'

Every clue so far has given a solid hint for where to look for the recipes, but this one is by far the worst; and it's the last one I need. All it says is 'west' and 'under a rock.'

West??? Where??? The map has no compass! West is swamp, and there was already a recipe piece there. I've combed the entire west half of the map, looking under every rock... but what if the left side isn't west??? I combed the east side too... nothing. What is this clue???

I can give you the locations of all the other recipe pieces, all I need is THIS ONE