Sandwiches are a booming, multi-billion-pound industry in the UK. In The Guardian, Sam Knight’s history of the modern British sandwich follows its transformation from a soggy excuse of a meal into a signature product of late-capitalist discipline. What made the story irresistible for me, though, are the people we meet along the way — from the Wembley factory workers stacking chicken on 33 sandwiches per minute to Julian Metcalfe, the tireless founder of Pret A Manger.

Soaring above them all, though, is Frank Boltman. A veteran filled-croissant innovator, his business never grew to the scale of the Prets of the world, but each of his multiple appearances in the piece comes full of compact, delicious morsels of sandwich wisdom.

“My idea of relaxation is to write down five new sandwiches,” he said when we met recently at his latest baby, a vaguely hipsterish place called Trade, on the Essex Road in north London. The quest of the sandwich inventor is a mostly pitiless one. The industry has its own 80:20 rule: 80% of sales come from 20% of the flavours. These are often referred to as “the core” – the egg mayonnaise, the BLT, the chicken salad – and they are as familiar as our own blood. Pret’s best-selling sandwiches (the top three are all baguettes: chicken caesar and bacon, tuna and cucumber, cheddar and pickle) have not changed for seven years. M&S’s prawn mayo has been its No 1 for 36.

Undaunted by this, Boltman starts out by choosing the bread, and the ingredients from those he is already using on his menu. The art of the sandwich designer is to think inwards, to find variations within a known and delineated realm. “It is a question of using tenacity, knowledge, know-how, flair,” said Boltman. People in the industry talk about seminal new combinations – Pret’s crayfish and rocket; M&S’s Wensleydale and carrot chutney – like Peter Brook’s Midsummer Night Dream, or Zeffirelli’s Romeo and Juliet. The story comes alive again. Someone finds a new move in chess.

It is possible to be a showman. Boltman talked about a chicken and broccoli bun he made in the 80s. “Granary seeded roll as a vehicle,” he said. “Unbelievable.” While we were talking, the kitchen made me Boltman’s interpretation of the Reuben, which he sells for £8.50. I hadn’t eaten that morning, and the pastrami, which had been cured for a week, lay deep. The taste of caraway seeds in the rye bread lingered in the roof of my mouth. “Did the secret sauce come through?” he asked.

Boltman has been round the block a few times. He had a McDonald’s franchise for a while. He observed that, even as sandwiches function as an accelerant of our harried, grinding lives, they also offer a moment of precious, private escape. “People want to eat,” he said, leaning close. “They want comfort. They want solace. I’ve had a shit morning. I’ve fallen out with my boss. I’ve had a fucking horrible journey in. A poxy lettuce-and-whatever concoction in a plastic bowl is not going to do it for me. I want a cup of tea, a chocolate biscuit and I actually want to cry. I am going out for a fucking sandwich.”

Read the story