Toast the cardamom in a frying pan (without oil) along with all the other ingredients up to and including the nutmeg, leave to cool.
Bring the water to the boil in a pan. Remove the pan from the heat, add the tea bags, cover and leave to steep for approx. 10 mins. Squeeze out the tea bags and remove. Add the sugar, vanilla seeds, vanilla pod, ginger and spices, bring to the boil, reduce the heat and simmer for approx. 10 mins. Pour the syrup through a sieve. While still boiling hot, pour into the clean, warmed bottles using a funnel and fill to just below the rim. Seal immediately and leave to cool.