Skim the scum off the surface from time to time.
Some solids should be visible on the bottom of the pan after about 30-45 minutes. When the smell becomes nutty or toffee-like, turn off the heat and allow the pan to cool slightly.
Filter using your chosen medium into a clean, dry airtight jar.

#Tip:

The final liquid should be amber and golden and smell a bit like toffee. Ghee will keep for months without refreigeration and even longer if solidified in the fridge.