As per the title.

I normally come up here on my own (and so eat a lot of fish and chips / sarnies / pork scratchings), but for the next week I’m up here with Mrs Giant. She’s not spent much time up here and so I want to convince her that The North Lakes area is more than coachfulls of blue rinses and tea shops….

So…somewhere posh for tea (dinner / supper) in Keswick / North Lakes area please (even better if it’s somewhere she (we) can get smart for (i.e. I put a shirt on, she puts dress on)!!

The Pheasant used to be good. Yon side of Keswick heading to Cockermouth. (adjacent to the Bassenthwaite lake IIR)

Here,
http://www.the-pheasant.co.uk/

Probably best to go to Morrels in town or the Lyzick just out of town

Not a personal recommendation as I haven’t been there myself, but it has a good reputation and might fit your requirements

http://www.armathwaite-hall.com/dining/lake_district_dining.php

Not northern lakes but we just spent 4 nights at the samling in Ambleside, the food & service were as good as we’ve had in a long time. If you can be bothered with the drive, I’d very much recommend it.