1. In a bowl, add glutinous rice flour, salt and sugar. Mix well. Then pour water over the flour. Mix well.
2. Transfer into a cooking pot. Cook over medium heat, stirring constantly until smooth and silky (usually it take about 2 to 4 minutes here).
3. Transfer the mochi onto your working board, then roll it out to about 5mm thickness with a rolling pin. Then cut into small pieces of about 2 x 2cm.
4. Place them onto a plate lightly covered with potato starch.
5. Let it to dry for 2 to 3 days. During this time, flip the mochis so all sides dry up and harden. Cover them at night.
6. After a few days, mochi must be hard. Add oil to a deep enough pan and heat over medium heat. Remove excess potato starch and dip the mochis in the hot oil (about 160℃). Turn the okaki occasionally, cook them until lightly browned (or more).