In a heatproof bowl, whisk together the glutinous rice flour and warm water until smooth and lump-free. If the mixture appears too thick, gradually add 3-4 tablespoons of additional warm water until it reaches the consistency of thick cream.

Cover the bowl with a heatproof plate and microwave on high for 1 minute. Using a wet silicone spatula, stir the mixture thoroughly, ensuring it is evenly combined. Return the bowl to the microwave and heat for another minute, or until the dough becomes translucent rather than opaque white. Note: Cooking times may vary depending on microwave wattage (tested at 1100W).

Since the cooked mochi dough is extremely sticky, keep the spatula wet with warm water to prevent it from sticking. If needed, lightly sprinkle the dough with warm water as you stir to maintain its elasticity.

Generously dust a plate with potato starch flour and transfer the hot mochi dough onto it using the wet spatula. Sprinkle additional potato starch over the top to prevent sticking. Allow it to cool slightly before handling.

Once the mochi has cooled enough to handle, divide it into small portions and gently remove any excess starch. The mochi is now ready to be used for various fillings or enjoyed on its own.