Grate the lauki/bottle gourd. I used the large size grater to grate the lauki.
In a wide pan, add about 1 tbsp of ghee. Fry the cashew pieces and keep it aside in a plate.
In the same pan add the remaining ghee and then add the grated lauki to the pan. Cook it on medium flame, stirring frequently.
When cooking the lauki, cover the pan as that enables to cook the lauki faster. Also make sure that you keep stirring the pan as the vegetable might stick to the bottom of the pan. If the lauki is sticking too much in the pan, sprinkle some water and then cook. This takes about 25 minutes and it is very important to stay close to the pan and be patient. The lauki has to cook entirely so that the raw smell of the vegetable is removed.
Once the lauki is entirely cooked and very soft, add the sugar.
The mixture would liquefy once the sugar is added. Keep cooking until the mixture thickens. This could take about 10 minutes.
Add the mawa and the cardamom powder. Reduce the heat to low and cook until the lauki burfi leaves the sides of the pan.
At this stage add the roasted cashews and mix well.
Transfer the lauki burfi to a greased plate and let it cool down. When the burfi has cooled down a bit, make lines with a knife to mark the burfi pieces.
Cut the lauki burfi entirely when it has cooled entirely. This can be kept in room temperature for a day or 2 and then can be stored refrigerated.