1. Place the sweet potato in a small saucepan with enough water to cover. Bring to a boil over a medium-high heat, then reduce heat to medium and cook for about 15 minutes until soft. Remove from heat, then strain and transfer to a medium bowl. Mash the potatoes with a fork, then set aside to cool.

2. Combine 60g of the glutinous rice flour in a small bowl with the just-boiled water. Stir with a spoon until it forms a smooth, stiff paste, then set aside in the bowl for the time being.

3. Stir the sugar and salt into the mashed sweet potato, then add the remaining 140g rice flour and the tap water. Combine with a fork until a shaggy dough forms, then add the hot-water paste. Knead gently together in the bowl, adding a teaspoon or two of extra water if it looks dry or crumbly. Turn the dough out onto a clean work surface and knead for about 5 minutes until smooth, pliable and no longer sticky. Place the dough back into the bowl, cover with a plate and set aside to rest for about 30 minutes.

4. Meanwhile, prepare the filling by scooping out 12 individual tablespoons of the sweet bean (or lotus) paste and place on a large plate. Each dollop should weigh 15g-20g. 

5. When the dough has rested, roll it into a long rope on a clean kitchen bench, then cut into 12 equal pieces. For best results, weigh each piece: it should be between 35g-40g (about twice the weight of the paste balls in the previous step). Roll into smooth balls then cover with a tea towel to prevent them drying out.

6. Working with one ball at a time, press a thumb into the centre and pinch around the sides to form a rough cup. Place a dollop of the filling paste inside this cavity and bring the edges up and over to enclose it completely. Roll once more into a smooth ball.

7. Place the sesame seeds on a small tray and have a small bowl of water close by. Wet hands in the water, then moisten the dough balls one at a time, then place on the tray of sesame seeds. Shake the tray so that the balls are completely coated in the seeds.

8. Fill a large saucepan with enough oil to come 5cm up the sides and place over a medium-low heat. When it registers 150C on a thermometer, use a large metal spoon to carefully lower a few balls into the oil and cook slowly for about 15 minutes until golden brown. Depending on the size of your saucepan, you may be able to get 4-6 balls into the oil without crowding them. Roll the balls around gently with the spoon to make sure they cook evenly. The oil should just simmer gently with tiny bubbles around the balls, so adjust the heat to ensure an evenly low temperature. There will be a little "puff" as the dough expands visibly around the 8-10 minute mark, so keep a slight distance as you continue to roll the balls gently in the oil.

9. Once they're golden-brown, remove the balls with a slotted spoon and place on a plate lined with paper towels. Repeat with the remaining balls. Allow to cool for a few minutes before serving.

This recipe was originally published in Good Weekend magazine