Divide the red bean paste into 12 equal balls. Refrigerate while you prepare the mochi.

Combine the glutinous rice flour, sugar and matcha powder in a microwave-safe bowl. Gradually stir in the water until smooth.

Microwave on high for 2 minutes. Stir well. Microwave for another 2 minutes and stir again. The mixture should be thick, sticky and slightly translucent. (Alternatively, steam for 20 minutes, stirring halfway.)

Generously dust a clean surface with potato starch. Turn out the hot mochi dough and dust the top. Allow to cool slightly.

Divide into 12 equal pieces. Flatten each piece into a circle. Place a ball of red bean paste in the centre. Wrap the mochi around the filling, pinching to seal.

Dust each mochi lightly with potato starch to prevent sticking. Refrigerate for 1 hour before serving.