The chai recipe I'm famous for is a synthesis of recipes from several ashrams I've lived at. I can thank the Hanuman Temple in Taos, NM and the Ayurvedic Institute for inspiring my love of chai. This recipe was then refined during my time at the Siddha Yoga Ashram in South Fallsburg, NY and at Ananda Ashram in Monroe, NY.
Like many Ayurvedic recipes, the chai ingredients have two purposes - they enhance the flavor and they are medicinal too. The stimulant effect of the caffeine in black tea is mitigated by the digestive benefits of the spices.
I usually just eye it, but I've tried to get more formal here:
Fill a large pot with 3 cups of water. Grate 3 Tbs. of fresh ginger into the water. Toss in 6 cinnamon sticks, 1 Tbs. whole cloves, & 1 1/2 Tbs. cardamom pods. Grate 1/4 tsp. nutmeg into the water. Bring to a boil and then simmer for 10 minutes. Add 3 cups of whole milk and turn up the heat. Do not walk away from the pot. Just stand by and sing and wait for the chai to froth up to the rim of the pot and then immediately turn off the flame or remove from heat. Now sprinkle loose Indian black tea to cover the entire surface of the chai. Indian Red Label or Taj Mahal is best. Stir and let steep for 5 minutes. Strain into a thermos and sweeten with raw sugar.
Traditional Indian chai is sweet, so to really be authentic, don't be frugal with the sugar. This is the best chai you'll ever have. Your friends will insist that you make it for parties and brunches. You may find yourself unable to drink store-bought or cafe chai ever again.