Divide salad greens among 4 plates, and then flan the Pomelo and cucumber on top of them. Arrange the prawns in the middle of the plate. Drizzle with dressing, garnish, and serve.
*Note: To segment the Pomelo, take a sharp paring knife and work it alongside the membrane of the fruit, carefully cutting out clean segments of it. If desired, the marinated, cooked prawns sold in the seafood department could replace the unflavoured ones used in this recipe.