On the stovetop, place the water over high heat and bring to a boil.
Add tea bags, cardamom pods and chai spice, lower heat and simmer for 20 minutes.
While tea simmers, combine sweetened condensed milk and half and half.
After 20 minutes, take off heat and strain tea to remove pods.
Cool completely.
If adding shots of espresso, brew them now and allow to cool before adding to tea.
When ready to serve, pour tea (and espresso, if using) over ice to about ¾ full.
Add milk mixture to taste.
Serve immediately.