Measure and add 2 cups full fat whole milk in a sauce pan and bring it to a boil in medium heat.
Once the milk reaches a boil, simmer it and place a ladle in the pan. It will prevent milk from boiling and spilling over. Now let the milk simmer for 20 minutes. Keep stirring and scraping any cream that gets collected once in a while and add it back to milk.
Once the milk has simmered for 20 minutes and reduced a bit, add the prepared rice flour slurry.
Mix well using the same ladle and simmer for another 3 minutes. The milk will be very thick and almost like custard now.
To the thickened milk add crumbled khoya and mix thoroughly. Maintain low heat throughout the process.
Next add the prepared nuts powder and mix.
Add cardamom powder and saffron threads.
Finally add 1/4 cup sugar and mix well. Sometimes when we add sugar at first, gauging the quantity may be difficult. So I prefer to add it after adding khoya.
Now stir everything very well and simmer for another 5-6 minutes. Sugar should be dissolved completely.
Remove from flame and let this mixture cool completely to room temperature. Now fill the kulfi moulds with this mixture. Cover with aluminum foil or parchment paper. You can insert an ice cream stick or popsicle sticks into each mold if you want.
Freeze these for 12-14 hours or until completely frozen.
To serve, gently dip the moulds in bowl containing water water for 10 seconds or rub them between your palms or you can even loosen the edges with a knife. Add some dried rose petals and chopped pistachios and serve kulfi immediately. You can also slice kulfi like they do in shops. It stays well in shape for quite sometime.