Take 1/2 cup of lukewarm water and add to it the maize flour along with the sour curd.
Blend it sufficiently in order to make a smooth batter.
Leave it aside for 30 minutes at least.
To the well mixed batter, add ginger green chilli paste, lemon juice, sugar, asafoetida, oil and the sweet corn kernels.
Mix it thoroughly.
To it, further add the fruit salt and blend it gently.
Transfer the batter into a 150 mm (6") diameter oil greased thali and steam for a period of 15-20 minutes.
To prepare the tempering heat the oil, and add to the heated oil, asafoetida, sesame seeds and mustard seeds.
Keep frying till you hear the seeds crackling.
Slowly pour the tempering over the prepared dhokla.
Cut the dhokla into pieces.
Wrap up the edges and roll the leaves, starting at their base and moving towards the tips.
Tighten the roll by sealing the sides with some paste.
Follow the same process for all the leaves and paste.
Put them in the perforated container of a steam cooker or a double boiler.
Steam them for 30 to 40 minutes till they get adequately steamed.
Cool them and then cut them into slices, each 1/2" thick.
If desired, the patras may also be deep fried.
For seasoning, heat oil in a pan.
Add the mustard seeds and cumin seeds to the heated oil and wait for them to splutter.
Then add sesame, cumin, and coconut to it.
Add salt, sugar and chilli powder according to taste.
Mix it well.