The team experimented with 38 kinds of rice from Sri Lanka,
    developing a new way of cooking rice that increased the RS
    content. In this method, they added a teaspoon of coconut
    oil to boiling water. Then, they added a half a cup of rice.
    They simmered this for 40 minutes, but one could boil it for
    20-25 minutes instead, the researchers note. Then, they
    refrigerated it for 12 hours. This procedure increased the
    RS by 10 times for traditional, non-fortified rice.  

    How can such a simple change in cooking result in a lower-
    calorie food? James explains that the oil enters the starch
    granules during cooking, changing its architecture so that
    it becomes resistant to the action of digestive enzymes.
    This means that fewer calories ultimately get absorbed into
    the body. “The cooling is essential because amylose, the
    soluble part of the starch, leaves the granules during
    gelatinization,” explains James. “Cooling for 12 hours will
    lead to formation of hydrogen bonds between the amylose
    molecules outside the rice grains which also turns it into a
    resistant starch.” Reheating the rice for consumption, he
    notes, does not affect the RS levels.

So the key ingredient is cooling for 12 hours. Simple, but not exactly in the sense a casual reader might infer from the title.