Mix glutinous rice flour, corn starch, and sugar together
Add milk and cooking oil to the dry ingredients and stir until smooth
Divide the mochi dough in half
Keep one half plain for original flavor mochi
Mix matcha powder into the other half for matcha flavored mochi
Steam or cook both portions of dough until soft and stretchy
Dust with cooked flour to prevent sticking
Fill each mochi with red bean paste
Shape into soft, stretchy mochi balls
