In a pot, mix in the milk, tea bags and spices over medium heat until the mixture boils.
When milk boils, remove from heat and let the tea bags steep for 3 minutes. After the three minutes discard the tea bags and boil the mixture again
In the meantime whisk the eggs, sugar, and cornstarch in a bowl
Carefully, temper the eggs, that means to bring up the temperature of the eggs without cooking. To do that, add a bit of the hot milk mixture into the eggs while whisking vigorously. Then slowly add the rest of the milk mixture. Do not stop whisking
Pour the whole mixture back into the pot and cook over low heat until the mixture thickens and covers the back of the spoon. DO NOT LET THE MIXTURE BOIL
Remove from heat and strain into a clean bowl. Whisk in the half & half, cover and chill for a minimum of 2 hours
For Chai Eggnog Cocktail
In a shaker add the chilled eggnog mixture, rum, and lot's of ice. Shake and pour into Martini Glasses