This milk liquid is nothing more than milk, which is boiled down over a high flame until finally a thick paste remains. After the paste is then sweetened, it is left to set. To make the burfi even richer, you can use a mixture of 2 parts heavy cream and one part milk instead of butter and milk.
Put the milk on the highest heat. When the milk begins to rise, lower the flame so that the milk boils steadily without rising. Stir regularly and evenly so that the milk does not stick to the bottom of the pot. The thicker the milk becomes, the more often you will need to stir. Use a wide wooden spatula to scrape along the bottom of the pot. Either lower the flame and stir moderately or stir vigorously on a higher flame. However, you must stir in any case so that the milk does not burn. When the milk becomes a paste and the spatula leaves a momentary trace, add the sugar as well as the butter. Continue cooking and stirring until the burfi becomes very thick and sticky. You make the milk until you think the milk can not boil down further. On it you make it a few min longer. Burfi is very tasty in itself, but if you want to vary the flavor, you can now add flavorings. Nuts, vanilla, toasted coconut, mixed cardamom. This the whole are typical flavors for