Combine the cold green tea and spinach in a blender. Blend on high until smooth and no visible pieces remain. Note: to make the twice brewed green tea, heat 1 cup of water until hot. Add 2 tea bags and steep for 4 minutes. Remove the tea bags and refrigerate the tea until cold.
Add in the Greek yogurt, frozen banana and frozen mango. Blend until smooth.
Pour into a glass and serve immediately.
To make twice brewed green tea, make tea as normal, except add 2 tea bags instead of 1.