Use the mug that you'll be serving your finished tea in and pour 1 and 1/2 'mugs' of water into your pot and heat to a simmer. Add in the cardamom, cloves, cinnamon and fennel. Let this simmer for 30 seconds to 1 minute.
Add in the teabags and nutmeg and allow everything to boil together for another 1-2 minutes. (Note: if you have some extra time and like a strong tea, at this point you can drop the temperature down to low and let the ingredients steep for 5-7 mintues and really flavour the water, this is optional).
Add sugar to the water. I add about 1 teaspoon per cup because I like a sweet tea.
Finally add 1 mug full of milk, and heat until boiling. It's important to bring the milk to a rolling boil to get an authentic chai flavour.
Strain the tea and serve!