2Boil the potatoes in a pot of water until they are tender, about 15-20 minutes. Drain and let them cool.
While the potatoes are boiling, place the eggs in a separate pot of water and bring to a boil. Once boiling, reduce the heat and let them simmer for 10 minutes. Drain and let them cool.
Peel and dice the cooled potatoes into bite-sized pieces.
Peel and chop the boiled eggs.
Dice the tomato and onion into small pieces.
In a large bowl, combine the potatoes, eggs, tomato, and onion.
In a small bowl, mix together the mayonnaise, mustard, salt, and black pepper.
Pour the dressing over the potato mixture and gently toss to combine.
Chill the salad in the refrigerator for at least 1 hour before serving.
Serve cold and enjoy your Potato and Egg Salad.