First saw a stall these at Wembley for an NFL game a couple of years ago. Absolutely gorgeous. They do a number of varieties. I like the Huge Pole and Big Dog the best. They have a really nice bite to them. Not too keen on the Brat though, but then I'm not a big fan of them anyway.
They have a website here
http://bigapplehotdogs.com/
However I found out at the end of last year they started selling online!
https://big-apple-hotdogs.myshopify.com ... s/sausages
They can send out frozen and they arrive defrosted or send out unfrozen delivered for next day delivery, although they only send out on Mondays and Wednesdays.
We've already had three deliveries from them at work (I managed to get two others on board with a sample!!)
Can't recommend them highly enough.