Mix all of the ingredients and strain through a fine-mesh sieve into a plastic tub large enough to hold the mixture.
Microwave in 2-minute intervals on medium power 4 or 5 times, stirring after each interval using a wooden spoon. At first it will look like something is wrong because the mixture will look chunky and some spots will be fluid while other have cooked. Keep microwaving and stirring until you obtain a smooth, homogenous, elastic dough.
Transfer the dough onto a surface dusted with rice flour. Sprinkle some rice flour on top and roll the dough out to about a 1.25-cm/.5-in thickness using a rolling pin. Keep adding rice flour under it and on top to keep it from sticking; turn it over frequently.
Let it cool, rest, and relax, covered with plastic.
Once the mochi has cooled, cut out disks using the dull end of a 2.5-cm/1-in ring cutter dipped in rice flour first. If you use the sharp end, the mochi won’t look very good; the dull end gives it that rounded “hamburger patty” look.