You will need to extract blue colouring from the flowers. To do this, wash and pound the flowers to extract a few drops of blue colouring.
Place a piece of muslin cloth at the bottom of a porous steaming pan. Put the rice, pandan leaves and add half the general santan to the rice. Steam over rapidly boiling water for 10 minutes. Add the rest of the general santan and continue to steam for 10 more minutes.
Remove the pan from the steamer and add the pati santan and salt. Mix well with a pair of chopsticks. Colour about a quarter of the rice blue and return to the steamer to cook it for 10 minutes.
Line a square tin with greased banana leaves. Spoon in the cooked rice, alternating the blue portion with the white rice. Mix well. Press down the rice with a banana leaf.
Cover the top of the rice with a banana leaf and weigh it down with a heavy object. Leave to cool. Cut into pieces and serve with kaya.