Place eggs in a saucepan with water to cover by 1 inch. Bring to a boil. Remove from heat; cover, and let stand 12 minutes. Drain; hold under cold running water until cool, then peel and chop.
In a medium bowl, combine eggs, Chutney Mayonnaise, onion, and a few dashes hot sauce; season with salt and pepper. Stir gently to combine.
Serve on toast, topped with watercress and sprinkled lightly with cayenne, as desired.