Take a sauce pan. Add 1 cup water and bring to boil. In goes the butterfly pea flower. I added some crushed lemon grass but it is optional.
Switch off stove and close with a lid. Let it steep for 15 minutes. In between you can give it a stir.
Now, wash rice well 2-3 times or until the washed water drains clear. Soak in hot water for 15 minutes.
After 15 minutes, fish out the flowers and lemon grass. You can eventually filter too. Start heating and bring to boil.
Now, drain water from rice completely. Add it to the boiling blue water.
Sprinkle required salt. Bring to boil again.
Put the flame to low and cook covered for 12-14 minutes or until all the water is absorbed. Do not cook in higher heat.
Check the bottom of pan for water. Switch off stove and fluff gently. Keep covered.
Do not worry even if some rice is stuck to the pan. The standing time will loosen up the rice making it soft.
After 10 minutes, the rice will be softer and fluffier.
Now heat a small pan with oil. Splutter mustard firstly, then add urad dal, chana dal followed by ginger, green chillies and curry leaves.
Transfer to the rice. Drizzle lemon juice and quickly give it a mix.
The color will apparently change to purple as lemon reacts with the rice it touches. Yet the blue hue will be there. It's done.