Heat 1 tablespoon ghee in a thick pan. Add the grated khova and saute well. Saute in low flame till the color changes and turns dark brown. Remove to a plate.
Take sugar in another pan. Add 1/4 cup water and mix well. Bring this mixture to a boil and cook in medium flame for 3-4 minutes. No need to check for string consistency. Just thick sugar syrup will do.
Now add the roasted khova and mix well. Cook in medium flame stirring constantly.
The khova sugar mixture will thicken and begin to leave the sides of the pan. Add cardamom powder if needed and mix well.
Quickly transfer to a greased tray. Level with the back of a spoon. Spread roasted chopped nuts generously.
Draw lines to make slices with a sharp knife while the mixture is still warm. Make slices after the burfi reaches room temperature. Store in airtight container. If storing for more than a day, store in refrigerator.
Notes
1. Roast the khova in low flame. 2. The color of the burfi depends on the quality of khova used.