In a small frying pan, melt the butter over medium heat. Drop the cashews into the pan, and toast until golden brown. Remove the pan from the heat, then sprinkle over the paprika and salt, and gently toss to coat.
For the vinaigrette:
In a small bowl, combine the seasoned rice wine vinegar with the white wine vinegar. Add in the shallot, and a pinch of salt, and then stir. Add the oil in a thin stream, while whisking the mixture thoroughly with a fork or whisk.
For the salad:
Arrange the sliced papaya on a serving plate, and pile the watercress greens on top.
Drizzle the salad with the vinaigrette, and garnish with the whole spiced cashews.
If you are serving the salad with the Chicken with Papaya BBQ Sauce, reserve half of the whole nuts for the salad, and chop the remaining nuts to garnish the chicken.