In this month of July, every Saturday the A333 of AirAsia X will operate the flight of MIAT Mongolian Airlines.
These are the Times and Dates:
23-07 1300-1430 XAX A333 9M-XXZ OM 137/138
30-07 1300-1430 XAX A333 9M-XXZ OM 137/138
So I think this is quite a special visitor in Europe.