Cut Eggs Lengthwise In Half. Place Yolks In Bowl; Mash With Fork. Mix In Mayo, Olives, Mustard, Capers, Tomatoes, Anchovy And Pepper. Mix In Parsley. Arrange Watercress And Tomatoes On Serving Tray. Pipe Or Spoon Egg Mixture Into Egg Halves, Mounding Slightly. Place Eggs Atop Watercress. Garnish With Nicoise Olives. Sprinkle With Paprika. Cover And Refrigerate Until Chilled.