How to identify delicious restaurants?

Some pubs have delicious food - others, not so much. The “gastropub” trend of a decade or so ago has died down a bit, but there are still gastropubs around. Most pubs are part of a chain (Greene King, Youngs, Fullers…) and the food is reliably standard - but not mind-blowing. (Wetherspoons food is cheap, but I would AVOID if you want a serious pub food experience. ;-)

English food is not the bland beige joke it was 50 years ago… the country now abounds with wonderful eateries that feature local produce and “nose to tail” gastronomy. The cheeses, locally raised lamb and pork and beef, berries, seafood, veg, etc. can be simply amazing. Check restaurant websites to see how they source what they cook: the more the site raves about their suppliers/farms and whatnot, the likelier you are to get a delightful meal.

I rely on personal recommendations, combined with Google reviews, Yelp, and Trip Advisor. Folks on this board will have some wonderful suggestions that you can look up and vet via the websites listed above. :-) Happy eating!

I look for "gastropubs"--I don't know if the term is still in vogue, but it perfectly describes the quality food I like to have with a quality pint!
I do a general google search and find travel blogs a good source for restaurant recs.

Frequent London visitor.

OP you are not required to consume alcohol in a pub.

If not enjoying Pub Grub I’ll peruse Time Out, Conde Nast, Nat Geo and Eater London websites.

My dining palette is perfectly content with pub grub.

Occasionally I’ll simply luck out and see a place that looks interesting and try it out. That happened with Tudkin Flavors of Malaysia in London. Happened to be buying flowers at the adjacent market. Checked the menu in the window. Came back for dinner.

I return to Tudkin during each London stay.

OK, I will take the bait....

What is delicious? It's different for each person.

If you want something spicy, there are a myriad of Indian or Thai restaurants in
England.

Also consider going to the city market for the midday meal and getting
something from a food stand - there, you can judge popularity by how
many people are at the stand, and it will probably be cheaper than a
sit-down restaurant, since that appears to be a factor for you.

Pubs are a great option for food as the menu with prices is usually displayed
out front, and again, you can peek inside and get an idea of how popular the
place is.

But really, half the joy of going someplace is exploring and finding something
that you enjoy. I might offer that your friend maybe isn't experienced in doing that.

I visited London in August and had a couple of excellent meals that were not at a pub--though I am fond of pub food. One was recommended to us by a relative who lived in the neighborhood--we wouldn't have been in the Islington area otherwise--a Turkish/middle eastern place called Kilis on Theberton St. The other restaurant was not in London but Whitstable--I had chosen to spend my birthday in Whitstable and thus researched the town's restaurant offerings for a special birthday lunch. It definitely needed to focus on the abundant fresh seafood in the harbour town and thus we ended up having a wonderfully delicious lunch at Birdie's--French food, lots of specials featuring what was freshly caught that day. So, I'd say do some research ahead of time, read reviews and see if reservations are required. I find that if I wait until I'm really hungry at the end of the day all I see are places that are full of people and nothing available for walk-ins; not usually a problem at pubs but other restaurants it could be.

What's delicious? Seems a subjective standard. Personally I dont search out restaurants online and i dont look up reviews before I go in. I'm looking at what's local to my accommodations and then I'm looking at the posted menues to see what strikes me.

One thing to be aware of with so many pubs, is that many are either Green King or JD Wetherspoons. Green King has 1,600 locations (more than McDonald's 1300 locations) with three in Bath. Most you'd never know, many being old established pubs with the most telling sign being that the menus are nearly all the same. Not a critique, I've enjoyed several, just something to be knowledgeable about.

I have several go-to-sources for eating in England. For Bath, Timeout is your best source. It has a wide-variety of options at different price points. I used it when I was in Bath last December. I ate at the Green Rocket (just around the corner from my hotel) which had amazing vegan dishes that even a meat lover would enjoy. Great place for breakfast or lunch. They also cover tourist favorites such as Sally Lunn and the Pump Room, both of which are great for a spot of tea.

Timeout also covers Oxford. Haven’t been there recently so I can’t give any recommendations.

If your travels take you to London, The Infatuation is my go-to-source.

...My friend who traveled to England before has warned me about the food on his trip...."

I'm intrigued about what the warning was.

Here’s what I do, wherever I am.

I open the Maps on my iPhone and type “restaurants near me” (or sometimes “[food type] restaurants near me.”) Then I click on the ones that catch my interest, read some reviews, look at the menu.

I’ve eaten in some brilliant places that way.

Food in England - particularly London - is excellent but I’d steer clear of pubs as eating places unless they’re particularly noted for their food.