In a blender, combine boiled sweet potatoes, milk, and cornstarch.

Blend the ingredients until the mixture is smooth.

Pour the batter into a cup, add black sesame seeds, and mix well.

Transfer the batter to a piping bag and pipe small, spaced-out dollops onto a parchment-lined baking sheet.

Cover the dollops with another sheet of parchment paper.

Use the bottom of a flat cup to press each dollop into a thin, round chip.

Bake in the oven at 100 degrees Celsius for 40 minutes.