Cut your sweet potato into large wedges and steam until tender, about 15 to 20 minutes.
Using a fork or potato masher make sure to get the mixture completely smooth. Stir in your sugar and salt until fully incorporated. Add in your tapioca starch in batches, letting the potato mix absorb completely. The dough should feel like play dough. If it’s sticking to your hand it’s too wet, you can add a bit more until it’s smooth and springy. Roll into 1 inch balls. Smaller is better than larger as they puff and expand during cooking.
In a medium pan heat 3 inches of oil to 350F/175c. Carefully add the mochi balls one at a time. Do not add too many at once or they will stick together. Stir the oil so that it is moving constantly until the crust has formed on the outside. You will know when they are done when they float (about 5 minutes or so) Carefully remove to a paper towel lined plate. Allow to cool slightly before eating
