Lunch in Cambridge

They've asked specifically for a relatively informal pub-style lunch. I think they're looking for something 'English'
Just wondering if anybody could give me a few suggestions? It needs to be in the main centre ideally. Maybe somewhere by the river? Or somewhere pleasant to eat at? Doesn't have to be dirt-cheap, but equally not somewhere very expensive.

It's not a pub, but Tatties is amazing. Just by Market square if I remember correctly.

It does the best jacket potatoes I've ever tasted, with a big choice of accompaniments. It does do other stuff too, but I can't remember what because the memory of the potatoes just eclipse it all.

It's not expensive and very convenient for the centre.

Hi

Some family friends are coming over from the States for a holiday to London, but have asked to meet up for a day in Cambridge. I've been a few times before so they've asked me to sort out travel and the likes, but they've asked specifically for a relatively informal pub-style lunch. I think they're looking for something 'English'
Just wondering if anybody could give me a few suggestions? It needs to be in the main centre ideally. Maybe somewhere by the river? Or somewhere pleasant to eat at? Doesn't have to be dirt-cheap, but equally not somewhere very expensive.

Sorry this is in the University forum, but I had no idea where else I could get a response!

Ta!