Add the potatoes to a stockpot and cover with water. Bring to a boil, then turn to low and simmer for about 10 minutes, or until you can pierce the potato easily with a fork. Drain, rinse with cool water and set aside until cool.
Combine the drained tofu, mayo, mustard and salt in a bowl. Mash the tofu and mix well.
Cut the cooled potatoes in half lengthwise. Scoop out circular holes using a melon baller or small spoon. Spoon some tofu salad into each hole and top with a pimento-stuffed olive slice.
Recipe by Kathy Hester from The Ghoulish Gourmet: A Bewitching Collection of Vegan Halloween Recipes copyright 2016 printed with permission.