In a heavy-bottomed pan, heat 500 ml of full-fat milk and bring it to a boil. Simmer for 10 minutes, stirring occasionally.
In a separate bowl, mix 2 tablespoons of cornflour with 50 ml of cold milk to form a smooth paste. Add this paste to the boiling milk and cook for another 5 minutes, stirring continuously until the milk thickens.
Add 200 grams of sweetened condensed milk to the thickened milk and mix well. Cook for another 2 minutes and then remove the pan from heat. Allow the mixture to cool down to room temperature.
In a separate bowl, whip 200 ml of fresh cream until soft peaks form. Gently fold the whipped cream into the cooled milk mixture.
Coarsely chop 100 grams of mixed nuts (almonds, cashews, pistachios, and walnuts) and fold them into the ice cream mixture.
Pour the mixture into an airtight container and freeze for 6-8 hours or until firm.
Scoop out the nut ice cream and serve immediately.