firstly, take a large cucumber and grate full.
squeeze off the juice. keep cucumber and juice aside.
in a large bowl soak 1 cup rice for 3 hours or overnight.
drain off the water and transfer to a mixi.
add ½ cup jaggery and ½ cup coconut.
also, add cucumber juice and blend to a coarse paste.
make sure to add cucumber juice in batches, else the batter may turn watery.
add grated cucumber and ¼ tsp salt to the batter.
mix well making sure everything is well combined.
add cucumber juice as required to adjust the consistency of the batter.
now take a large piece of banana leaf and grease with ghee.
pour 2 ladleful of batter and fold the banana leaf.
make sure the batter is well sealed without overflowing.
now steam the idli for 25 minutes or until it is cooked completely.
finally, enjoy cucumber idli with ghee or with honey.