You can get this by playing a solo match on the UK board with only one computer opponent. Try to start with tickets that connect or go through London, if you don't get any just back out and start a new match until you do get some. From there you need to prioritize claiming every route around London. If the AI takes a single one you will need to start over and try again. (in a 2 player match there is no using the 2nd track on a 2 color route).
Once you have claimed all the routes in and out of London, you will need to complete your tickets to try and maximize the points you will receive. I recommend drawing multiple tickets and hoping for short easy England only routes that involve London since you have it secure. When I earned this I had completed 6 tickets.