Step 1

Bring ginger, cinnamon, and 3½ cups water to a boil in a medium saucepan over medium-high heat. Lower heat and simmer rapidly, stirring occasionally, until liquid is reduced by a third and very fragrant, about 20 minutes.

Step 2

Remove pan from heat, stir in tea and cardamom, and let steep 2 minutes.

Step 3

Return pan to medium-high heat and stir in milk and maple syrup. Cook, stirring occasionally and keeping a close watch, until mixture begins to foam up and boil, about 5 minutes. Immediately remove from heat and let sit 5 minutes. Strain chai through a fine-mesh sieve into a teapot or pitcher and serve.