Boil water first, add choco chips in a heat resistant bowl, using double boiler method melt the chocolate.You can use cooking chocolate too.Set aside.
To a mixing bowl add butter, sugar.
Beat well until creamy.Crack open the eggs and add it.
Beat until smooth and creamy.Add vanilla essence, mix well.
Now in another mixing bowl place a sieve, add wheat flour,coco powder,baking powder to it.
Add salt to it and sieve well.
Now add little of sieved flour to butter egg mixture, alternate with milk starting and ending with flour mixture.
Mix well to form a smooth lumpfree batter.
Add melted chocolate mix once.Grease a oven safe bowl with lots of butter.I placed a small circular butter paper at the bottom for easy demoulding.
Transfer the prepared mixture to the bowl.The pudding rises well so choose a bowl accordingly.Grease a butter paper(I forgot but please do it), place over the bowl then wrap it with silver foil.
You can either use your steamer or pressure cooker.Put a plate inside the cooker, add water to it.Place the pudding bowl on the plate.Water should be touching 1/3 rd of the bowl.Close with lid, no whistle needed.Steam cook for 1 hour 30 mins. In between check the water level and add water accordingly.Check after 1 hr then proceed.Insert a knife in the centre of the pudding if it comes out clean then the pudding is done else steam cook for few more mins.
Mine got done in 1 hr 30 mins.Remove from flame, set aside for 10 mins.Gently remove the covers,Then slide a buttered knife at the edges.
Then invert, remove the butter paper.Cool down completely atleast for 30 mins(meanwhile you can make the chocolate sauce) then slice and serve.