I agree with earlier recommendations about Pat Chapman. He's the Godfather of BIR (British Indian Restaurant) curries. For a slightly more modern take, there's Dan Toombs, "The Curry Guy", who is pretty much following the same path as Chapman did decades ago. (I have several books from both.)
I'm not a fan of watching The Hairy Bikers on the telly. (Far too much scripting and if Si King says "dude" one more time I'd like to punch him in the face.) However, their books are really excellent. They have one entitled "Great Curries", which contains recipes from various countries. It's worth a look. (I'm in love with their Asian Adventure book.)
For more authentic Indian curries, Camellia Panjabi's "50 Great Curries of India" is good.
Having spent many years in Asia, I can say that the "authentic" food (ie that eaten by the locals) bears little or no resemblance to the food served in UK restaurants purporting to be Indian/Thai/whatever. Sure, some Asian ingredients are hard to source in some areas but the average British person has very definite expectations about what they want from a curry and that tends not to coincide with the taste of the real thing.