I used the BBC Good Foods recipe for a cottage pie, however I thinly sliced the onions so they cook slower and sweat differently with the carrots and celery.
People also told me the red wine doesn’t matter, however I chose some rather fruity and full bodied wines with the sauce/gravy - I think this really made a difference and the flavours really pop. I tried weaker red wines and they just don’t bring out the flavour in the same way.