My FIL shared a little bit of folk history about this dish as well. Newly married couples invited to people's homes for virundhu (rougly translates to lunch or dinner invitation) were often served this dish as a custom. Beyond that none of us have any idea what the significance of the dish itself is.
Sounds and looks like a lot of work but it is not. If you have the sandhavai press the rest is easy. The batter is made with regular idli rice, steamed in idli moulds, stuffed into the moulds and then pressed to get string hoppers. No fermenting of the batter is required.
The string hoppers are served with sweetened coconut milk for the sweet version or stir fried for the savory version with flavors ranging from tomato,lemon, tamarind to spicy coconut.
Sweet - Plain with coconut milk
Sweet and Savory Sandhavai / Idiyappam (string hoppers)
1. 4 cups of par boiled rice (idli rice) - soak for 3-4 hours or enough to grind
2. Salt to taste
For the Sweet
2. 2 -4 cups of coconut milk (tinned would work
3. 2 cardamom pods powdered
4. 4-5 tbsp of sugar
For the Savory (4 cups of sandhavai)
5. 1/2 cup chopped onions
6. 4-5 green chilies chopped
7. 4 tomatoes chopped
8. seasonings: cumin, mustard, curry leaves
9. 1 tsp turmeric powder
10. 1 tsp of oil and salt to taste
For the Sandhavai
1. Grind the soaked rice to a very smooth pourable consistency (don't worry about too thin a consistency, everything works )
2. Grease the idli moulds and pour the batter and steam cook for 10-12 minutes
3. While still hot stuff the idlis into the press and press to get the sandhavai.
4. Set some aside for the sweet and roughly break apart the other half for the savory version
1. Heat oil in a flat bottomed pan and add the seasonings
2. Add the onions and green chilies and saute till they start to turn translucent
3. Add the turmeric powder, salt and tomatoes and saute for a minute or two
4. Cover with a lid and let it cook for 8-10 minutes till the tomatoes are soft
5. Mix in the sandhavai and turn off the heat
1.In a sauce pan add the coconut milk, cardamom and sugar and heat the coconut milk through stirring. Take care not to boil the milk or let it curdle
Serve over the plain sandhavai