Peel the potato and cut into one-inch cubes. Place in a microwave-safe bowl and cover with plastic wrap. Cut a small slit to vent. Microwave for 5 to 7 minutes until tender.
Add the milk to the potato and mash the potato mixture with a fork or pastry blender well. Let cool a bit.
Stir in the egg, cornstarch, cheese, breadcrumbs, salt and garlic salt. Mix well.
Place the dough between two pieces of wax paper. Press or roll the dough to 3/8-inch thickness. Use a two-inch circle cutter to cut circles. Place the potato circles on a baking sheet lined with parchment paper. If the dough is too soft, place in the refrigerator to chill 30 to 60 minutes.
Use a straw to make eyes and a small spoon to make smiles on each potato circle.
Bake for 10 to 15 minutes until the tops start to brown.