Place a saucepan on low heat, add the remaining milk and all of the sugar and stir until the sugar dissolves.
Once it boils, stir in the custard milk, give it a good mix, and simmer for a few minutes before turning off the heat.
Cool completely. To prevent the film from forming on top when you cool it quickly, place a layer of plastic wrap on the surface of the custard milk.
After 2 hours, take the container out, and either 1. put the whole thing in the blender, or 2. use a whisk it all together. You’ll see that the edges have frozen sooner that the middle. Whisk or blend to break up the ice crystals, and keep it back in the freezer.
Repeat the above process after 2 hours.
After another 2 hours, repeat the process of whisking/blending, and place it back in the freezer.
Your ice cream will be ready to consume after 8 hours in the freezer.
Equipment: A saucepan, an aluminium or freezer safe shallow container with a lid, a blender or food processor.