Add all the ingredients to a saucepan kept over medium heat.
Bring the mixture to a boil while stirring occasionally.
Switch off heat and serve immediately.
Notes
Traditionally, haldi ka doodh or turmeric milk is made with 3 key ingredients - milk, turmeric, and a sweetener of choice usually honey, jaggery, or sugar. There are a few popular variations though as shared below.
Ginger + honey - This combo has been considered beneficial for soothing a nasty cold or a cough. Take a one-inch piece of ginger and smash it using a mortar and a pestle till the ginger lets out its juice. Squeeze the juice out of the ginger. Add this juice along with the turmeric powder to milk and boil. Sweeten it with honey just before serving.
Pepper + jaggery or sweetener of your choice - Take about 5-6 whole peppercorns and crush them into a fine powder. Add this pepper powder along with turmeric, jaggery, and milk to make golden milk with a hint of heat.
Tips
It is best consumed immediately while it is still warm though you can refrigerate for a day or two.
If you are using honey as a sweetener, it is recommended that you add it to the milk just before serving. Honey should never be heated as per Ayurveda.
Start with 1/2 teaspoon of turmeric for every 1.5 cups of milk. You can increase the amount as you develop a taste for it.