I went to the Royal Quarter Cafe at Wellington House, 70 Buckingham Gate, and saw they had matcha latte on the menu! (pictured) so I ordered it and it was okay. I did have to put two cubes of brown sugar to combat some of the bitterness! It did make me crave green tea frappucino with red bean! (yes red bean… its lovely) I was introduced to that when I went to Starbucks in Busan last year.