Kewpie mayonnaise has swiftly become a household name over the past few years. At least, in Ollie’s house it has. They get through enough of the stuff to make them question whether they’d actually cook anything without it.

Take your bog-standard mayo: creamy, tangy, perfectly respectable, but ultimately the sort of condiment you squeeze onto something and promptly forget about. Kewpie is different. Kewpie wants attention.

So when I was invited down to the KEWPIE IT. pop-up in Covent Garden, my +1 was particularly excited. Not because of the promise of a beautifully designed Japanese konbini, or even the prospect of a Tamago Sando, but because they were seemingly prepared to overdose on Kewpie.

And, to be fair, there were worse ways to spend an afternoon.

The pop-up’s premise was to celebrate the humble ingredients behind the iconic Japanese egg sandwich: soft bread, boiled egg and a generous amount of Kewpie. On paper, it sounds almost aggressively simple. In reality, the result was an unctuous, creamy Tamago Sando that made a pretty convincing argument for why mayonnaise deserves more respect.

Kewpie’s richness isn’t accidental. It’s made predominantly with egg yolks rather than whole eggs, giving it a noticeably fuller, silkier texture and deeper umami flavour. The vinegars add acidity, keeping all that richness in check.

The Tamago Sando really lets those qualities show off. The egg and mayo almost melt into one another, creating something rich without becoming overwhelmingly heavy. It’s the sort of sandwich where you take a bite, pause for half a second and think: why is this so much better than an egg sandwich has any right to be?

Although, I don’t actually think I’ve had an egg sandwich in the last 20 years. If Kewpie had appeared earlier in my life, I may have become an egg sandwich connoisseur. An ESC, if you will.

Then came the cucumber salad, bringing a welcome hit of freshness and zing. It was a useful reminder that Kewpie isn’t just for drowning an egg sandwich in. Its savoury character works just as well against something crisp and acidic, and the brand’s KEWPIE IT. campaign is essentially built around that idea: a squeeze can transform sandwiches, salads, burgers and vegetables from everyday to something a little more exciting.

And perhaps that’s why Kewpie has managed to go from Japanese supermarket staple to something that now seems to live permanently in so many people’s fridges. It’s still mayonnaise, but a more decadent, umami-heavy and, frankly, slightly addictive version of it.

My +1 may have arrived with plans for a Kewpie-induced overdose, but I left with a slightly more considered conclusion: sometimes the difference between a fairly ordinary lunch and a bloody good one really is just a squeeze of mayo.