Add the milk and sugar to a pot and stir it together. Since evaporated milk doesn't really absorb sugar, only add regular milk to the pot. Follow the same steps as below.
Turn the heat to medium and occasionally stir as it comes to a boil. When it thickens it will become easier to burn so reduce the heat to low and stir constantly.
You'll know it's done when it has boiled down by about half and becomes very thick...If you boil it just a little bit more, you can enjoy some milk jam.
Place in a sanitized jar and store in the refrigerator. It will be good for 1 week. You can use it with strawberries or on shaved ice.
This "Authentic Chinese-Style Shrimp with Mayonnaise" uses this condensed milk. Recipe ID: 2367654.
Story Behind this Recipe
Since I can't ever completely use a whole carton of condensed milk, I make this only when I need it. The basic recipe is [Milk: 100 ml + Sugar: 1 tablespoon]. So if you just remember that the finished amount is half of that ratio, you can make the amount you need whenever you need it.
Please take care not to burn it. You can also use the microwave but there is the chance that it will bubble over, so please use a large heat-proof container. The amount of time it takes to cook is when it has boiled down to half the amount, so if making in the microwave, take it out and stir it occasionally to check.