Whisk egg yolks and 2 tablespoons sugar in medium bowl to blend well.
Combine milk, cream, tea leaves, and remaining 1/2 cup sugar in heavy medium saucepan. Bring to simmer over medium heat, stirring until sugar dissolves. Gradually whisk hot milk mixture into egg yolk mixture; return to same saucepan. Stir over medium-low heat until custard thickens enough to leave path on spoon when finger is drawn across, about 8 minutes (do not boil). Immediately strain sauce into small bowl. Refrigerate uncovered until cold, at least 4 hours. (Can be made 1 day ahead. Cover and keep refrigerated.)
Preheat oven to 375°F. Generously butter 6-cup soufflé dish; coat dish with sugar.
Combine milk and 5 tablespoons sugar in heavy medium saucepan. Stir over medium-low heat until sugar dissolves and milk comes to simmer.
Remove from heat; add both chocolates and stir until melted and smooth.
Whisk in egg yolks.
Using electric mixer, beat whites in medium bowl until soft peaks form. Gradually add 3 tablespoons sugar, beating until stiff but not dry. Fold whites into warm chocolate mixture in 3 additions.
Transfer mixture to prepared dish.
Bake soufflé until just set in center and top is puffed and cracked all over, about 32 minutes.
