Cut the watermelon, removing the rind and cutting into bite sized cubes
Add the diced cucumbers and diced onion
Drizzle with olive oil and red wine vinegar
Season with salt and pepper. You need more salt than you think. (I like to strain the extra watermelon juice at this point).
Add everything else except feta & mix well.
Crumble feta cheese on top but don’t shake so the cheese doesn’t become water.
