I may have mentioned it before, but it's a point worth repeating. On the continent there's a clear understanding of the difference between a restaurant and a bistro or a ristorante and a trattoria. The chosen name emblazoned over an establishment tells you what sort of expectations you may have, both about the kind of food on offer and about the price. To take the Italian example; in a trattoria you can expect decent food that isn't elaborate, surroundings that are spare but clean, no great choice on the wine list and you can expect to pay a modest amount for your fare. A restaurant makes you different promises. A better-appointed dining room, a good wine list, attentive service, more elaborate food and a much higher price. Here in Ireland the nomenclatures are blurred: I've been in bistros that charge restaurant prices and in restaurants that serve bistro food. It's a pity, because that simple distinction lets you know from outside on the street whether it's the sort of place you're looking for at a given moment.

When Marian Kenny said she'd like to go to an Italian restaurant in Dalkey called Don Giovanni she was being accurate - 'restaurant' is what it says above the door. Yet this is a classic trattoria; busy, bustling and reasonably priced. It's the sort of place you might take a bunch of kids for a pizza before or after treating them to a movie. It's not designed or intended for a long lingering dinner, it's there to serve the particular niche that the trattoria traditionally does. We'd been sitting for a while before I began to realise this - I was still thinking in terms of restaurants - but as I looked around I began to recognise the familiar buzz of a trattoria, very similar to those that I know and love in Italy.

The wine list has a couple of dozen wines, mostly Italian, and most of them are listed at under £15, which is very unusual and very welcome. The house wines are under a tenner. If you wanted to splash out there's a good Amarone and Barolo listed, but otherwise you can buy a wine for significantly less than the same wines are listed elsewhere. We picked the Collavini Pinot Grigio at £13.75, which I've seen priced as high as £18. Another pleasure is to find a big bottle of mineral water at £1.50, something I'd like to see a lot more often. The menu is a laminate folded in three which starts with a page of starters. Exactly as you'd expect it has things like Caprese salad, crostini, bruschetta but also non-Italian things like smoked salmon and prawn cocktail, all priced between £2.75 and £4.50. There's a dozen pastas priced between £6 and £8 with classics like Bolognese, carbonara, arrabbiata and Amatriciana; a dozen pizzas also priced between £6 and £8 with three classics, Margherita, Quattro Stagioni and calzone and some idiosyncratic ones; plenty of meat, fish and poultry dishes including a few classic Italian dishes like chicken cacciatora and diavolo, veal with lemon and saltimbocca. Most of the main courses are under a tenner, the most expensive being the fillet steak at £12.95, and they all come with vegetables and potatoes.

Marian, who isn't renowned for her large appetite, chose a minestrone soup to start and ravioli in a rose sauce to follow. I decided to test the kitchen and chose two difficult dishes: calamari because they're so hard to get tender, and saltimbocca alla Romana, which needs a subtle hand to get the flavours of sage, prosciutto, veal and wine to blend properly. We sipped our wine and Marian, who lives nearby, told me that this was a place she liked to drop into for a quick meal and a glass of wine - something that seemed to be entirely sensible.

When the starters arrived I was pleasantly surprised. As I said at the beginning, I normally set my expectations by the price I'm required to pay; so perfectly cooked calamari and a well-made soup made a good start to the meal considering the cost of the two dishes came to just over £7. I began to feel comfortable, Don Giovanni's was giving me just the sort of food that I like and it wasn't expensive. But the real surprise came when the main courses arrived. My saltimbocca alla Romana looked perfect. Thin slices of veal covered the plate with a sauce of just the right consistency while the smell that drifted up to my nostrils brought Proustian memories of meals in Trastevere under Roman skies. Gingerly I took a bite. Could it live it up to my expectations? Not only did it, it was good enough to make me refuse to taste Marian's pasta, so fearful was I not to confuse the tastes that I was enjoying with other flavours. Marian's ravioli looked good on the plate; a tomato sauce thinned with cream giving it the pink colour to which it owed its name and although not a big eater, she made great inroads into it. A small flat of vegetables that accompanied the meal was left mostly untouched by both of us - a pity because they were well-cooked and well-flavoured.

We thought we might wait for a while before ordering desserts and just finish the wine slowly. But even after a pause I could find no urge for something sweet and a look at the menu didn't change my mind. Like most Italian restaurants, desserts appear to have a low priority. Tira mi su, profiteroles or ice-cream offered me nothing to titillate an already happy palate, so instead we finished with a couple of espressos, which were good. There's a long listing of after dinner drinks and liqueurs with lots of Italian favourites like Strega and Sambuca, but my own personal favourite for the post-prandial slot, Fernet Branca, sadly wasn't on the list.

I liked Don Giovanni's for its simplicity and lack of pretension. There has to be a place in our burgeoning gamut of restaurant types for the trattoria and its ilk, after all we don't always want a long, lingering four-course dinner. I'm glad Marian introduced me to it, and a bill of £43.50 made it, I think, the most reasonably priced dinner of the year.