Remove the rind and pips from the watermelon, and cut into approximately 4cm triangular chunks.
Cut the feta into similar sized pieces and put them both into a large, wide shallow bowl.
(I would probably not add the feta till later...)
Tear off sprigs of parsley so that it is used like a salad leaf,
rather than a garnish, and add to the bowl along with the chopped mint.
Tip the now glowingly puce onions,
along with their pink juices over the salad in the bowl,
add the oil and olives,
then using your hands toss the salad very gently so that the feta and melon don't lose their shape.
Add a good grinding of black pepper and tast to see whether the dressing needs more lime.