Wash and combine chana dal, urad dal, tur dal and rice. Soak them for 4-5 hours.
After 4-5 hours, all the grains will swell.
Now grind them to a fine consistency. Keep this batter for overnight fermentation.
The next day, add salt, turmeric powder, red chilli powder, grated bottle gourd and chilli and ginger paste to this batter. Mix well.
Add yoghurt and mix.
Transfer this batter to a baking mould.
Prepare the tempering by heating oil in a pan and adding all the tempering ingredients - asaphoetida, cumin seeds, sesame seeds, mustard seeds and curry leaves.
Add this to the batter.
Transfer to a preheated oven and bake at 200 deg C for about 35-40 minutes.
Insert a toothpick and check. If it comes out clean, the Handvo is fully cooked.
Once fully cooked, remove it from the oven and let it cool for at least 10 minutes before de-moulding it.
Now the Handvo is ready. Cut it and serve it with chutney.