Add the butter to a pan on medium heat and let it melt.
After a while, you will see white foam on the surface.
Let it simmer and bubble away 20-25 minutes on low flame. Do not stir.
You will start to see the milk solids at the bottom of the pan.
From this moment carefully observe, because the milk solids must be caramelized without burning and this point of caramelization gives the authentic flavour of traditional Ghee.
With a knife separate the foam from above to observe the bottom of the pan. If you see that the solids of the bottom are dark brown colour, turn off the heat.
The whole process usually takes about 35-40 minutes.
Put a thin cloth on top of a strainer and strain the ghee into a clean jar.
When it is completely cooled it becomes semi-solid. Normally you can store it at room temperature, but if you want, you can put it in the fridge. This way it will last longer.