Dry roast nuts until crunchy and set aside to cool. Later fine chop them. Heat milk until slightly hot. Keep this aside.
To a heavy bottom large pan, add ghee and heat it on a medium flame.
Add ragi flour, coconut and semolina. Mix to combine and roast on a low flame until aromatic. Keep stirring constantly to avoid burning.
You may taste test to ensure the flour doesn't taste raw any more.
Turn off the heat and add sugar and pour milk. Mix well to make sure there are no lumps.
Turn on the heat and begin to cook on a low heat until the halwa thickens.
As it cooks all of the moisture will be absorbed and the ragi halwa begins to leave the sides of the pan.
Add cardamom powder and continue to cook until the halwa comes together to a mass.
At this stage you should see some ghee releasing from the halwa. Turn off the heat.
You may serve ragi halwa warm with some fine chopped nuts. Alternately transfer to a tray lined with parchment paper. Transfer the halwa to the tray and sprinkle nuts. Press down and set it in the fridge overnight. Later remove and cut to pieces . You will get a soft set halwa and not dry burfi.
Store ragi halwa in a air tight jar and refrigerate for a week. You may reheat it in the microwave.