Put the milk in a heavy bottom pan and place the pan on a medium flame.
Once the milk comes to near boil add the yogurt so as to curdle the milk.
We are not removing the pan from fire. Instead let it simmer on slow flame, stirring occasionally.
In a heavy bottom kadai or wok put the ghee and add the edible gum, once the gum cooks and swells up (which will be very fast) remove it immediately and add the fried gum to the curdled milk.
In the same kadai which will have some ghee remaining add the wheat flour and roast it till it turns light pink. Once the flour is lightly roasted add it to the simmering milk mixture. The mixture will look like a curdled porridge.
Again in the same kadai, add the sugar and allow it to caramelize to a light amber color. Be very careful here. If the sugar is caramelized more it may start tasting bitter and will make the Halwasan bitter.
Add the caramelized sugar to the milk mixture. Keep stirring until it the mixture is thick enough and leaves the sides.
Conduct a test, take a pea sized mixture and if it forms a ball and holds its shape the mix is ready.
Remove from flame. Add the nutmeg and cardamon powders. Mix well.
Once the mixture has come to room temperature, shape it in lemon sized balls, flatten it a bit and decorate with almond and pistachios.