If you can not sun roast the spices, the other option is to dry roast them for a minute. Dry roast the cloves, peppercorns, cinnamon and cardamom for a minute, stirring continuously.
Allow them to cool completely.
In a mixer grinder or a coffee grinder grind the cardamom, cloves, cinnamon, mace and nutmeg to a fine powder.
Add the dry ginger powder to the powdered spices and run the grinder one more time to give the spices a good mix.
Transfer the Chai Spice to an airtight container.
Use as required in your daily cup of tea or Chai spiced milk or as required.