There's lots of novelty acts in Bangkok, and a proper British pie shop is definitely a novelty act. But novelty or not, the pies are some of the best I've tasted. The pie shop is at 14/45 Sukhimvit 65 (shown on the map below) and sells a range of traditional British pies: Steak & Kidney, Meat and Potato, Shepherd's Pie (a potato topped pie) even a pork pie but without the traditional jelly, together with a range of chutneys.
My friends tell me that a 'meat and potato' pie is now called a 'potato and meat' pie in Britain because they have to list the main ingredient first. Potato is cheaper than meat so they fill it with potato. They also told me you can't get good pies anymore, they are all meat slurry in pastry cases made by machines. But here there is far more meat than potato and the quality is far better, real meat pieces and rich gravy.
There's also a Tavern from the same company that also sells the pies, on Soi Thonglor 8-10 (Soi means street, side streets are numbered and major streets also have names. Soi Thonglor is the name of side street 55 off Sukhumvit road). When I visited they had a Harley Davidson night. So you can see a Thai group singing British punk hits in Harley Davidson dress in Bangkok Thailand!?
Find it at the green arrow below.