Method:

1. Clean vazhaipoo as mentioned in the link above and soak in buttermilk until use, Keep aside. Then dry roast jeera for few mins until aroma comes then grind it to a semi fine powder.
   
2. In a pan, heat oil - add mustard seeds, urad dhal let it splutter. Then add curry leaves, green chillies, onion and garlic, moong dhal and saute until onions turn slightly browned.
   
3. Drain buttermilk / water then add vazhaipoo, turmeric powder and saute for a minute. Then add water till immersing level and allow it to boil and cook till the veggie turns soft. Saute for few mins until the moisture evaporates and the curry becomes dry and roasted. It may take 5 -7 mins then add grated coconut, roasted jeera powder and stir well for 2-3mins. Switch off.
   

My Notes:

• You can even cook vazhaipoo and moong dhal in a pan with water. But I prefer pressure cooking. Moong dhal should not be mushy, it should be firm yet soft to bite.
• Dont skip roasting moongdhal, it gives a nice aroma.
• Amma always adds coconut only after switching off any poriyal as raw coconut is not much of cholesterol she says so using it as raw as much as possible is good.