Grease and line a 7" square baking tin with baking parchment. Alternatively you can grease a round 8" plate (thali) or even a clean working surface (like a chopping board) with ghee and keep it ready.

Place the water and sugar in a large. heavy based kadhai or wok and over a medium heat cook the mixture till the sugar dissolves completely.

Mix the cocoa powder into the butter till smooth and no lumps remain.

Add the condensed milk and the butter-cocoa mixture and cook on a medium - medium high heat stirring every now and then till the colour changes and the mixture thickens.

When the mixture starts to form tiny bubbles at the edge of the pan, pay attention. From now on give it your undivided attention and stir until the mixture begins to leave the sides of the pan and forms a big lump. Add the chopped cashewnuts and mix well. Remove pan from heat.

Transfer the contents of the pan into the prepared baking pan and level the surface using the back of a spoon.

Let the toffee cool a bit before scoring the top into squares. Allow to cool completely and then cut and serve. The toffee will harden once it has cooled.