Remove the skin and seeds from the sweet pumpkin, then cut it into bite-sized pieces.
Put the sweet potato and sweet pumpkin in a steamer and steam for 15 minutes.
Boil the eggs until hard-boiled, then peel them.
Cut the steamed sweet pumpkin, sweet potato, and boiled eggs into small pieces.
Place all the ingredients in a bowl, add mayonnaise, salt, and pepper, and mix well.
Plate the salad and serve.