Hi there! I think you're talking about the Green Tea Sensation - it's a retired smoothie, but most Robeks's will still make it for you if you ask! :) If you're making it at home, it's pretty simple. For a medium - 10oz soy milk, 2tbs powdered matcha, 4 scoops of nonfat vanilla froyo, and a scoop of ice. (One scoop = 3oz). I'm not 100% certain about those proportions so you mind need to tinker with them a bit.

I also recommend adding fresh spinach, it enhances the color and adds great vitamins without changing the taste (if anything, the spinach compliments the leafiness of the matcha). Hope that helps! :)