Clean, peel, and slice the potatoes into thin cuts. Steam the sliced potato for 10 minutes at 100°C.

When the potatoes are soft enough to mash, mash them with a potato masher or fork and mix with salt, black pepper powder, and cornstarch.

Mix the ingredients well and shape into a ball. Using a rolling pin, roll the mixture into a thin sheet.

Make the smiley face shape. Use a cookie cutter or bottle cap to make the round face, chopsticks to make the eyes, and a spoon to form the smile. (Optional: Freeze the smiley face fries in the freezer for 30 minutes or more to make them firmer before frying.)

Heat a pot with oil for deep frying. Fry the potatoes in hot oil at 356°F until golden brown. (Optional: Cook the smiley face fries in an air fryer at 360°F or 180°C for 10 to 15 minutes. Flip the smiley face fries halfway through the cooking time to cook the other side evenly. You can also bake it in the oven for 15 to 20 minutes at  400°F or 200°C.)