I like to champion culinary underdogs. Barley coffee, for example, which I drink in the morning. Mustela, a cured, slightly peppery pork sirloin from Sardinia. Or verjuice, the juice from unripe grapes, once a core part of Italian medieval recipes.

I am always on the lookout for lesser-known ingredients - which is why I set out for a long walk along the streets of Milan to find a cheesemonger rumoured to stock a near extinct breed of cheese from Lombardy.

Lombardy, you see, is the unsung hero of Italian gastronomy. In a country where every second village has a reputation for olive oil, wine or some other foodie marvel, Lombardy is chiefly known for being the productive heart of Italy, a land of factories, banks and no-nonsense people with a near-Calvinist approach to work. It is a place full of serious men in suits who stride purposefully across Milan’s financial district to make real money at the Stock Exchange. But it only takes a look at its rich, fat soil peppered with cows and it becomes clear that this is also dairy land worth exploring.

Indeed, some research and talks with local friends revealed Lombardy has a long cheese tradition, which legend wants to have started before the Romans arrived in 222 BC.

Even its cheeses’ names - Scimudin, Bitto, Taleggio - hold an alluring, almost exotic promise. One in particular drew me more than others - candid, soft, creamy Crescenza. Its unusual name means focaccia, because, much like focaccia, this cheese ferments and swells if kept in a warm environment. And swell it did, mushroomed in fact, sadly giving birth to a million industrial versions which invaded supermarkets across Italy in the last few years - each cheese more fat-free than the previous one, each with a longer use-by date, whereas the true essence of Crescenza lies in its plump transience.

Real Crescenza - creamier in winter, sturdier in summer - has almost vanished, so finding it became a mission for me - but where to look? My friends endlessly praised La Baita dei Formaggi, a Milan shop which has been making and selling cheeses since 1880. They all mentioned in passing that it had a wide selection of local cheeses, making it sound like a good bet.

And so it is that I find myself charging down a maze of former blue-collar streets where sober turn-of-the-century buildings that once housed working families are now pricey, impossibly hip lofts for boho-chic Milanese, while the workshops on the ground floor have been turned into rows of dimly-lit pubs and stylish cafes strewn with fake zebra skins. Suddenly, I turn a corner and the robust smell of cheese - that indefinable mix of milk, fat cows and grass - wafts from a shop well into the street.

La Baita stands inconspicuously by the side of a sullen thoroughfare lined with dismal post-war architecture which has remained true to its working class origins. It is much smaller than I would have expected for a celebrated gastronomic mecca. No swanky windows, mood lighting or designer windows here. Just honest, dark wooden panels covered from floor to ceiling in accolades and diplomas, and pristine shelves crammed full with cheese.

As I enter, I notice that lines of precious Parma ham have been relegated to one side of the door just opposite the till - unusual for an Italian store. But here pride of place goes to cheeses large and small, baby-blue and snow-white, jelly-soft and rock-hard that Umberto, the burly man behind the counter, surveys with a proprietorial eye.

He is not the owner, I know that. My research tells me the shop belongs to one Roberto Rusconi, who personally selects La Baita’s cheeses one by one. Although I have no idea what he looks like, I picture Signor Rusconi out and about in the fields, chewing the grass, sipping the milk, sniffing the cheese, then giving it the thumbs up or down, regal like a Roman emperor.

His choice of cheeses is certainly imperial and his taste impeccable. There are countless fat Parmigiano wheels piled neatly in niches carved into the wooden wall panels, the obligatory Pecorino rounds squatting solid and earthy in a corner of the refrigerated counter, and an aromatic fontina from the Alps sitting primly on a wooden shelf. But, true to promise, most of La Baita’s shelf space goes to cheeses from Lombardy. Triangles of creamy, mouldy Gorgonzola, proudly showing off its stink of cave and ancient times. Flirty goat’s cheeses, prettily arranged as miniature wheels robed in herbs or spices. Misshapen squares of Stracchino, glistening white like a lily on the counter’s top shelf, just under my nose.

And here, buried behind an army of soft cheeses, is my elusive quarry. Real, artisanal Crescenza, peeking tremulously from under a simple paper wrap in the far corner of the fridge counter. It’s so white it is almost religious. It speaks of innocence, purity, christening dresses from the day lace was popular and beige was just white gone dirty.

I point. Umberto nods and cuts. As the soft, creamy cheese leaves behind a candid streak, he reassures me that they make it themselves.

We speak, Umberto and I, of wine - a chardonnay they make in the Veneto - and sweet condiments La Baita sells to match with strong, masculine cheeses like Parmigiano.

“Like Membrillo with the Spanish Manchego cheese,” I say.

He is suitably impressed. “Have you been here before?” he asks.

Clearly, I must have passed some sort of cheese knowledge test. As I say that, no, I live in London most of the time, he proudly reveals they stock Stilton and Cheddar. “The real deal, you know, not that orange, plasticky stuff.”

This is an almost unheard feat in a country that sees Britain as the epitome of bad food and I know I should be making appropriately complimentary noises. But my heart isn’t in it. Together with my palate and my brain, it is racing after the little bite of Crescenza tucked in the shopping bag Umberto just gave me.

The trip back home is a pleasurable agony of anticipation. Open the door, rush to the kitchen, take out a plate. Then finally I lay almost trembling hands on it. Under the impact of the fork, it collapses in rivulets, a cheese that can’t bear to be cut.

It tastes as pre-dawn light should: soft beyond softness, enveloping, barely sweet. And just after I have taken in the gentle aroma of milk, just after it coats my mouth, Crescenza shows its mettle with a persistence that speaks of yogurt and grass. It’s a triumph of mildness, a proof that less is indeed more, a celebration of barely-there flavours, which cling to the tastebuds with the tenacity of a dying breed.

I have never met Roberto Rusconi and probably never will. But the man who saved this cheesy miracle from the brink of industrial oblivion deserves a place in gastronomic paradise.
La Baita del Formaggio, Via Foppa 5, Milan, www.labaitadelformaggio.it