The Menus tend to be pretty much the same wherever you go.
The usual array of Fish & Chips, Burgers, Chicken, Scampi and Salads. Steaks & Mixed Grills are also common place.
Add to this a selection of sandwiches/rolls/baguettes/sub rolls (same fillings, just different bread casings).
Some hostelries will offer 'Chef's Specials', so you may get Chinese, Thai or Indian (or Polish, depends where the chef was born))
Everything is served with Chips (or Jacket Potato if you wish) - why not Mashed Potato?
One dish (one of my favourites actually) I have never found on a Pub Menu is Shepherds Pie.
Why? Easy to prepare, easy to heat up. And I'm willing to wager that it would sell by the bucket load (this is not a serving suggestion!)
Not just Pubs - the same applies to the "Feed The Family For a Fiver" places (Beefeater, Harvester, Sizzler etc)
Put Shepherds Pie on your Menus - You Know It Make Sense