STEFANO Crescenzi taught me how to make risotto. It was on a stove in the cavernous kitchens of the Italian ambassador's residency back in 1999, and probably counts as my first ever cookery lesson.

Not everyone knows who Stefano Crescenzi is, or indeed David Izzo, but if you love great coffee and authentic Italian food, you're probably a regular of theirs without even knowing it. It's no secret that La Corte del Caffe' serves the best coffee in the capital, nor that Dunne & Crescenzi's antipasti, washed down with a smooth Chianti, will transport you to Italy in seconds. Then there's Bar Italia, where you'll find genuine Italian fare at wonderfully affordable prices.

The only area the savvy Romans haven't ventured in to is pizza, but that's set to change with the imminent arrival of their new restaurant in the IFSC. "They say Romans shouldn't eat pizza anywhere else as it just won't taste as good, " Stefano explains with a grin. He is the older of the two, 48, with wiry grey hair, a round, open face and twinkling blue eyes. David, at 32, is slim, smartly dressed and a fluent French speaker. He speaks immaculate English too, scattered liberally with colloquialisms that reveal his 10 years in Dublin.

Both are proud, passionate Romans who arrived separately in Ireland in 1995. Stefano came with Eileen, his Irish wife, whom he'd met through their work in the UN.

David, only 22, came to improve his English so he could become an air steward with Alitialia.

When their paths crossed in 1999 Stefano was wholesaling Italian produce . . . coffee, olive oil, wine, cheese, pasta, pesto . . . and David was managing a small Italian deli on Chatham Street. Stefano had already run a deli with Eileen in Sutton for two years before deciding to look for a city-centre location. Alongside a successful stall at the Temple Bar market, the wholesaling business was going well and Stefano invited the young David to become an agent. Shortly afterwards the pair was approached by the soon-to-open Epicurean Food Hall, on Liffey Street, and asked to take a unit.

"They didn't want us selling our wines though, so we agreed to try a cafe and deli, " Stefano recalls. "At the same time Eileen and I had signed a lease on South Frederick Street where we opened Dunne & Crescenzi."

Dublin didn't have much in the way of authentic Italian outlets in the mid-'90s, and certainly nowhere with really great Italian coffee. Tucked off the main Nassau Street strip, news of the continental-style deli was slow to spread, and it wasn't until the introduction of wine by the glass at its counter that Dunne & Crescenzi really flourished. "Even then the punters only trickled in, " Stefano explains, "until we got a good write-up in the national press."

So while we might think we were a pretty cosmopolitan bunch back in 1995, David and Stefano discovered otherwise.

"When we arrived here there were no direct flights to Rome and only three or four per week to Milan, " David explains. "People were interested in Italian food and culture but the demand just wasn't there."

He recalls his first foray into the lucrative coffee market here, selling espresso from a coffee cart outside Murphy's newsagents and sandwich shop on Baggot Street. "For the first few days we managed to sell one or two cups max! It was a total disaster, despite the fact that O'Brien's, nearby, was doing a roaring coffee trade." Seeing as they'd bought a licence and paid Murphy's a fee to use their electricity, David and his friend decided to stick it out and began handing out free coffees for a number of days. "Amazingly the following week we sold about 50 cups the first day, that grew to 100, and eventually peaked at about 300 a day. The hardest part had been convincing the Irish to try something new."

Fast forward to 1999, when David faced daily queues of caffeine lovers who'd discovered that La Corte's espresso (made with Palombini coffee, before you ask) is the finest for miles around. The Italian deli served interesting sandwiches too, crammed with Italian delights like creamy mozzarella, peppery rocket and Parma ham, and these proved so popular that Stefano soon developed the menu to include a selection of hot dishes.

Despite Stefano and Eileen operating one company and David and Stefano operating another, the concept has remained the same across the board . . . quality produce, welltrained staff and affordability. This recipe for success has seen their Roman empire spread to include Bar Italia, a large restaurant in Dublin's Italian Quarter, several more La Corte outlets, a second branch of Dunne & Crescenzi in Sandymount, L'Officina at Dundrum Town Centre and the newly opened Nonna Valentina. "It didn't make sense to keep opening the same concept in different locations, " David explains. "People would get fed up very quickly if there were 10 Dunne & Crescenzis around the city. Besides if you owned 10 pubs you'd never give them all the same name."

Nonna Valentina, named after Stefano's grandmother who was a big influence on his cooking, occupies the original premises of Kevin Thornton's Michelin-starred restaurant in Portobello, and is the newest, and more upmarket member of the family. Its opening last year was eagerly anticipated by the partners' many foodie followers, and, even more so, by Ireland's restaurant critics. "We couldn't believe the speed with which they appeared over the first three days!"

Stefano exclaims. "When a play opens the critics are invited to an opening night, which has been carefully choreographed. But a restaurant isn't like theatre, and can't be stage-managed, as there are so many variables. I couldn't believe how little mercy there is here." In saying that, Nonna Valentina received pretty favourable reviews, but Stefano still objects to this siege mentality. "We employ over 100 staff (the majority of whom are Italian) but we actually train over 300 a year. With that volume of people it's impossible to have everyone perfect for opening week. Everyone needs time to learn, improve, tweak. The Irish critics don't make allowances for that."

Stefano isn't looking for kid gloves; when it comes to criticism, he's quick to levy it at his home town, which has a lofty reputation for great cuisine. Citing poor service, overpriced food and even . . . heaven forbid . . . bad coffee, he feels standards can be raised everywhere. "We feel certain that we serve a better cappuccino here than most you can get in Rome, " he boasts. "Go to Piazza san Lorenzo and see how we compare."

"Coffee is quite misunderstood, " David picks up. "Essentially it's an ingredient and deserves due consideration. It may seem like an easy way to make money but unless staff are properly trained then customers get inferior products and feel like they're being ripped off. The price of a cup reflects the expertise required to make it great."

Both men are firm believers in good staff training and feel that, compared to Italy, standards of food and training are higher here. But not when it comes to their native cuisine.

Neither goes out to Italian restaurants in Dublin. "I'd rather eat in one of our own places, " Stefano clarifies, "even though it's probably not an ideal way to relax!" He finds food shopping difficult in Ireland and can't understand why there's no city-centre butcher on the southside of town. "There are only a few fishmongers too. It's terrible! I miss shopping in Rome, where you could pop out to buy whatever you needed in any district. Fish wrapped in plastic from the supermarket fridge isn't my idea of good food."

Neither partner has managed to find great pizza in Dublin either, although David doesn't mind Ciao Bella Roma on Parliament Street. "We'll be branching into pizza when our new 130-seater premises opens in the IFSC over the coming months. We plan to expand our importation of food too and are interested in creating our own brand."

Before leaving I throw one final question at the dynamic duo, expecting an impassioned response. "Pineapple on pizzas?" Stefano exclaims. "I refuse to even try it!" Thus follows a black list of potential crimes against pizza, with chorizo, bell peppers, sweetcorn and pepperoni all making the black list. So I guess we won't be ordering the Hawaiian 16" any time soon down the IFSC.