yeah so sausage in the USA is wildly different from sausage (what we call sausage) in the UK.. American sausage, often called 'breakfast sausage' is quite course, has no filler (bread as in the UK) and is heavily seasoned and usually has a sage aftertaste.. British sausage (what we call a banger) is very soft minced pork , lightly seasoned with pepper and ground together (minced) with bread or rusk to absorb the juices more. UK sausage is plump and even tender, inside a crisper skin, whilst the American stuff is more meaty and herby.
The British varieties of sausage (like Cumberland or Linconshire) can not be found, even Irish sausage is unheard of. However, you can buy some really, really good 'German' sausage, Brats and other varieties that are much much closer to the UK banger. I particularly like some of the Polish style sausage available here and those would make quite decent 'bangers and mash' and indeed, that is something I regularly feed my hubby.
On the 'mash' topic.. using a ricer or masher is a very British thing.. the thought of me ever using hydrated potato (smash in the UK) was horrific.. I have chastised many an American when they even suggested the idea of making mash from a packet.. that was until I tried their version .. and I must admit it is rather good. Idahoan mash, in packets, comes in loads of 'flavours' and is very easy to make and, seriously, I find it very hard to tell the difference from my lovingly crafted, riced, buttered and seasoned mash that takes me a while to make, to this packet stuff that literally is boiling water and mix.. It is available in the UK too.. I am quite a fan and rarely mash now.
So, Bangers and mash in the USA is a real possibility.. Use 'Turkey Gravy' (sold in jars in the grocery store!!) as the 'Bisto' and it is then only a small step to making your own batter, and enjoying 'toad in the hole'.. Its very easy and makes an amazing (and very British) meal.