I love olan. In the initial days after I had turned vegan, we used to have a monthly potluck consisting of only WFPB food. And there were prizes for the top 3 dishes, decided by popular vote. I was always tempted to make olan, but desisted. Mainly because olan has a very subtle taste. And I, mistakenly, thought that the audience comprising a mixed crowd, but not from Kerala, might not appreciate it. When I finally presented this dish, after several months of self-debate, it was a super hit! I had underestimated the very sophisticated tastebuds of my fellow vegans.
I must confess that several Malayalee friends were shocked to discover that I use pumpkin in my olan. Traditionally, one can use just ash gourd or a combination of ash gourd and pumpkin. I love both versions.

Ingredients 
1 medium sized ash gourd (safed peta, kumblanga)
1 cup pumpkin pieces (sitaphal, mathan)
6 green chillies, slit
1 cup coconut milk, thin or medium consistency 
1/4 cup red oriental beans (vanpayar, red cow peas, karamani payir, red lobia) – use white lobia if the red one is not available)
150 gms string beans (lobia, long beans, payaru) – optional
1 sprig curry leaves
Salt to taste
Method
Soak the red cow peas for about 5 hours or overnight
Cook in a pressure cooker, adding salt and just enough water, for 3-4 whistles (the beans must be cooked, but not mushy)
Cut the ash gourd and pumpkin into very thin 1″ slices
Chop the string beans into 1″ pieces (if using)
Open the lid of the pressure cooker, once cooled
Transfer to a vessel
Place it on the flame
Add sliced ash gourd, pumpkin, green chillies and chopped string beans
Mix well and add 1/2 cup water
Cover with a plate and cook for about 5 minutes
Remove the lid
Adjust salt
Add curry leaves
Add coconut milk and stir gently
As the mixture is coming to boil, remove from flame (do not actually boil)
Serve hot with red/brown rice
Enjoy!