Mix together the semolina, buttermilk, vegetables, ginger-green chilli paste in a bowl. Set aside for half an hour.Grease a thali. Boil sufficient water in a steamer.
Add the fruit salt, one tablespoon oil and salt to the batter and mix well. Pour into the greased thali and steam in the steamer for ten to fifteen minutes. Allow to cool and cut into squares or diamonds.
For the tempering, heat the oil in a small non-stick pan and add the mustard seeds. Once the seeds splutter, add the sesame seeds, asafoetida, curry leaves and dried red chilli. Pour this tempering over the dhokla and serve warm.