The Wall Street Journal once described the sandwich as Britain’s “biggest contribution to gastronomy”. It was a backhanded compliment. The story, which appeared on its front page, went on to declare that “barely edible sandwiches dominate the landscape” in the UK. And perhaps this was once true. I’ve often bemoaned the lack of good, independent sandwich shops in London, the kind you find on almost every corner in New York and LA. Despite living in the country that supposedly invented the sandwich, we’re far too content with flimsy supermarket versions. But times are changing and London chefs are leading the way.

But first, a short history lesson. If Mr John Montagu, the fourth Earl of Sandwich, hadn’t asked for salt beef served between two slices of bread over 250 years ago, we might’ve been deprived of the classic lunch staple that’s migrated around the world and back. The story goes that the Earl asked for this particular serving so that he could eat while playing cards and his friends asked “to have the same as Sandwich”.

The Earl of Sandwich had almost certainly seen stuffed pitta breads on his travels in the Eastern Mediterranean. And from vada pav in India to chacarero in Chile, and back to jambon-beurre in France and our own chip butties, there’s a universal genius, and decided practicality, to putting something delicious between bread.

And yet, before the M&S prawn mayo became a bestseller in the 1980s, sandwiches in the UK were usually ham, with a little mustard if you were lucky.

In How To Eat, Ms Nigella Lawson makes the case for the bacon sandwich: “Nothing is as good as a bacon sandwich made with white bread. There are times when you just need to have that salty-sweet curl of seared flesh pressed between fat-softened, rind-stained spongy slices.” Best not to get into a debate about condiments. Passions run high when it comes to bacon. Though food writer Ms Felicity Cloake suggests going off-piste with a combination of marmalade and English mustard.

One of the best bacon sandwiches in London can be found at St John Bread and Wine. Even better when accompanied by a glass of chilled Breton cider, according to chef proprietor Mr Fergus Henderson. If you’d rather grab and go, head to Borough Market for spicy chorizo rolls from Brindisa or Kappacasein cheese toasties. Monty’s Deli is the place to go for New York-style Reuben sandwiches, piled high with house-cured salt beef or pastrami. The original and still the best, if you’ll allow a bagel to be counted as a sandwich, is Beigel Bake on Brick Lane. Opened in 1974, it now sells more than 2,000 fresh bagels a day, filled with peerless salt beef and hot mustard.

The Dusty Knuckle Bakery in east London is the current favourite among sandwich connoisseurs, serving up generously filled rolls and slices of sourdough with unique combinations such as braised purple sprouting broccoli with romesco and feta, or charred celeriac with Lincolnshire Poacher cheese, mojo verde and herb salad. Then there’s Bodega Rita’s in King’s Cross, where Ms Missy Flynn and her team are taking inspiration from the ubiquitous corner stores in New York and LA, pairing sourdough sandwiches, Vietnamese banh mi and Peruvian sánguches with natural wines and craft spirits.

Everyone knows that any sandwich, especially a dreary one, can be improved with a layer of ready salted crisps. Mr Max Halley takes this notion to heart at his sandwich shop in Stroud Green. He adds shoestring fries to his take on the gastropub classic “Ham, Egg ’n’ Chips” and sprinkles Bombay mix in “The Bhaji Smuggler”. Max’s Sandwich Shop is a restaurant pretending not to be a restaurant. Mr Halley trained as a chef and each carefully-wrapped parcel brought to the table is essentially a meal between two chunks of focaccia. Try, for example, an “Et Tu Brute? Murdering The Ceasar” – roasted guinea fowl with pickled grapes, tarragon salsa, chicory, garlic croutons and anchovy mayo – and you’ll notice the intricate balance of hot, cold, sweet, sour, crunchy and soft, the six elements Mr Halley believes make a great dish. For those unwilling to make the pilgrimage, Max’s Sandwich Book is the ultimate guide to creating your own sarnie of dreams at home.

New to the London sandwich scene is Visions Canteen in Shoreditch, a collaboration between the team behind Hackney Road’s Lanark Coffee and chef Mr Matt Scott, formerly head chef of Bad Sports taqueria. They’ve taken inspiration from their favourite cuisines to put together a menu of sandwiches, and only sandwiches, that tour the world. Try “The Grapow” – spicy ground chicken, pickled cucumber, Thai basil, coriander and crispy shallots – and take the time to eat in for the added bonus of crisps and giant dill pickles on your plate.

If you’d rather relax in more salubrious environs, perhaps with a cold martini in hand, order the smoked eel sandwich at Quo Vadis in Soho (or learn how to make it yourself, here). Or try souped-up versions of nostalgia-inducing classics at two of London’s most anticipated recent openings: the ham and cheese toastie at Cora Pearl is the most elegant toastie you’ll ever eat, and the fish sandwich at St Leonard’s is essentially a luxe version of a Filet-O-Fish.

But if you’re of the opinion that sandwiches shouldn’t be too fancy, then a slew of new London openings will bring a smile and sate your hunger. The duo behind innovative Hackney restaurant Pidgin will soon be opening Sons And Daughters, a sandwich bar in Coal Drops Yard. The award-winning street-food vendor Sub Cult is about to open its first permanent site in the City. And Ms Freddie Janssen will be launching her long-awaited Snackbar this summer, serving mortadella banh mi, meatball subs and kimchi cheese toasties on Dalston Lane.

So it’s official. London sandwiches are, once again, the greatest thing since, well, sliced bread.