Once it has heated up a little, take out 3 tablespoons milk from the pan into a small bowl. Add in 3 tablespoons custard powder to that milk and mix well. There should be no lumps. Set it aside.

Stir the milk in the pan in between and let it heat up and come to a gentle boil. Then lower the heat, add sugar and mix until combined.

Cook for 2-3 minutes until the custard thickens. Remove pan from heat and let it cool down a bit. At this point you can also add rose water and cardamom powder (if using). Then cover the custard and place in the refrigerator to chill.

Start adding the custard mix. Add little at a time and mix after each addition. Whisk continuously. 

Cover and refrigerate the custard for 1 to 2 hours after mixing in the fruits for the flavors to develop....