Place a sauce pan on medium-high heat. Add water, grated ginger, gently crushed cardamom pods and let the water come up to a simmer.
Add tea leaves (or tea bags) and bring everything to a rolling boil.
Add milk and bring the tea to a full boil again. Reduce the heat to medium-low and let it simmer for a minute. Turn off the heat.
Using a fine mesh strainer, pout the tea in two cups. Add sugar or honey to taste, if using. Enjoy!
Notes
Ginger: Use fresh ginger for the best results. Wash and dry ginger and scrape off any bruised skin with a spoon or vegetable peeler. Peeling the entire ginger is optional and purely based on personal preference (I don't).
Adjust the flavor: This quantity of ginger gives the tea a prominent ginger flavor. The quantity of ginger can be adjusted to suit your preference.
Add masala: Add ⅛ teaspoon of tea masala (chai masala) to the saucepan along with ginger and cardamom, and enjoy Masala chai.
Make it stronger: To make a strong cup of tea (Kadak Chai), add an extra ¼ cup of water and milk each, and simmer the chai for 2 to 3 minutes.
Make it creamier: For a creamier chai, add 1½ cups water + ¾ cup milk instead. Alternatively, use full-fat milk.
Storing: Ginger chai gets darker in color and a bit bitter in taste if reheated multiple times. If making a larger batch, store it in a thermos and use it as needed.
Strain: Use a fine-mesh strainer to strain the tea to avoid any tea leaves from transferring over to the cup.
The nutrition facts below are my estimates based on two 12-ounce cups of tea without sugar. If you follow any diet plan, I recommend cross-checking with your preferred nutrition calculator.