In a bowl mix together besan, rice flour, salt, red chilly, chaat masala, kasuri methi and ajwain.
Add the curd, water and oil and mix to form a thick batter.
Add the baking soda and give a nice stir until the batter turns fluffy.
Grease a mW oven proof bowl and pour the batter into it.
MW on high for 6 minutes. Test the cake for doneness with a tooth pick.
Once done, remove from oven and let it cool for 5 minutes.
Flip on to a plate. If necessary, trim the top to fit it neatly on the plate.
Use thin buttermilk to brush the sides of the cake. Let the cake absorb the buttermilk before brushing more.
Heat oil in a pan and add mustard. When it crackles, add the sesame seeds.
When it starts crackling, pour it on the cake.
Top with coconut and coriander leaves and serve immediately.