Only 2 of the 5 waiting staff were Thai and the menu did not have Thai language subtitles to the menu items - always an indicator of lack of authenticity in my opinion. And thus it was. To call this restaurant Isarn, a region of Thailand famed for its spicy and distinctive range of food and then not have one authentic Isaan dish on the menu is laughable. There was the odd dish that mimicked an Isaan dish but the one I had - char-grilled chicken with papaya salad - had thick julienne of hard green papaya, rather than the grated and softish green papaya. Not at all like the papaya salad ('Som Tam') of Isaan fame.
The 'prawns and thin noodles' was not a bad rendition of the Thai dish 'Yam wun Saen' and the Mixed seafood in spicy sauce was excellent and inexpensive in Thai restaurant and seafood terms, despite being not similar to any Thai dish I know of.
So, based on an admittedly small sample of their dishes (and a take-away 2 years ago), observation and having eaten Thai widely in the UK and Thailand I would say the restaurant:
- is low on authenticity and is dumbed-down on spice for us Brits
- serves reasonably nice tasting food for all that
- is not a rip-off on price like some Thai restaurants (my wife's £6.20 175ml glass of Pinot Grigio did seem way overpriced, until I tasted it. My £3.50 bottle of Chang was as cheap as it gets in the UK)
- has perfunctory service which gets stretched later on when the restaurant is full
- has waitresses who engage in no conversation with customers (very unusual for Thais not to converse with other Thai customers like my wife and kid). Curious grey butchers apron kit too!
- people who want a reasonably tasty semi-spiced range of Asian-fusion type dishes without worrying about authenticity and content with efficient only service will not be disappointed
Generally I have found that Thai restaurants in mid size UK towns are better and more authentic than in London. I'd better try out Heron Bar (Bayswater) today! I live in Isaan and Bangkok - for 7 years, but have also tried many UK Thai restaurants on return visits to the UK.