You may have noticed; I enjoy a good dinner. I like lunch too, and I still remember the last lines of the Cautionary Tale of Henry King - 'Oh my friends be warned by me, that breakfast, dinner, lunch and tea are all the human frame requires. With that the wretched child expires.' Myself, I tend to manage on less than four meals a day, but I have observed that for the most part lunch is a faster meal than dinner, less relaxed and less intimate. I know, before anyone chooses to point it out, that there can be long and relaxed lunches; I know, I've had a few. But in that great tradition of generalising wildly, I am going to stick with my theory that dinner is for slow food and slow eating.

Anyone who dines out must occasionally ask themselves 'How come lunch always costs less than dinner, even if the food is essentially the same?' The simple answer is that for most restaurants, dinner is for making money and lunch is for generating a bit of cash flow, as well as being a showcase for what's on offer for dinner - it's better value from the food point of view. We would balk at paying sixty quid for lunch for two, but will pay it for dinner. Now all this talk of lunch is occasioned by a visit this week to The Red Onion in Dun Laoghaire, a small restaurant on the main street where I've had some very good lunches. The food was good enough for me to take my mother there, a lady who cooks extremely well and is not easy to please when it comes to food. Since I knew all this, when I heard that they had recently begun to open for dinner I felt impelled to try it.

My wife and I arrived mid-week and got a table without a booking. As soon as we sat we got a menu and wine list, and ordered a bottle of mineral water, which turned out to be Ferrarelle, one of my favourites. The wine list is very short, nine wines in all, but they are moderately priced - all under £20. With such a narrow choice finding a wine that suits the mood isn't easy, but I settled for a Spanish wine, a Piedemonte Cabernet Sauvignon at £14.50 which both Susie and I liked; full and robust, with a lot of fruity undertones.

There's a distinctly Mediterranean feel to the food in The Red Onion - their use of basil, olive oil, balsamic vinegar and roasted vegetables contribute to this. The menu is full of interesting dishes, there's roasted goats cheese salad, smoked salmon and crab meat roulade and cream cheese, black pudding crostini, oven baked ciabatta topped with vineripened tomatoes (where else do tomatoes ripen?), black pudding and fresh Italian mozzarella, garlic mushrooms on toasted ciabatta, all around £5. Main courses, too, are in the same vein: chicken stuffed with basil and sun-dried tomatoes, Barbary duck with cranberry jus, salmon and cream cheese in a parcel, sirloin steak and Sambuca chicken, all of which include house mash and wok-fried vegetables in the price, which is mostly around £10.

Susie chose the goats cheese to start and followed with the chicken stuffed with basil and sun-dried tomatoes, while I chose the salmon roulade to start and the duck for my main course. With that done, it was time to soak in the surroundings. The dining room is long and narrow, there's a counter just inside the door with tables beside and in front of it. Beyond that, where we sat, there are tables on both sides of the room, the centre being a passage to the loos, which are at the back. When I was here for lunch I hadn't really taken in the surroundings, but like I say, dinner is slow-time and this time I did.

The floor is made of large stone tiles, the walls are painted and are decorated with a few paintings and a couple of wire sculptures. The tables are canteen blue melamine and the chairs, although lightly padded, are hard. A long banquette runs down one side of the back of the restaurant with a padded seat and a plain, wooden backrest. The overall effect is Spartan, the tables, floor and walls making the room seem hard and cold. Bright halogen spots and night-light candles on the tables made up the lighting.

Our starters arrived and Susie's goats cheese salad made her very happy. Not just a tasty cheese, but a well-dressed salad of mixed leaves with the sort of taste that continentals take for granted. My starter was also nicely presented, the salmon and crab very good indeed, but the pastry surround somewhat less successful. Our main courses were also tasty, Susie and I trading morsels and enjoying the fresh, clean, almost Cal-Ital flavours. Both her chicken and my duck were served on a bed of mash with the plates decorated around the edges, while the vegetables came on a separate flat.

So here we were enjoying good food at reasonable prices and being served with efficiency and attentiveness. These are the ingredients that normally make me relaxed and comfortable, but my chair was getting the better of me, cutting off the blood supply behind my legs. Only constant shifting and twisting seemed to work, causing Susie to remark that I seemed unusually fidgety. I found myself thinking that here's something that separates lunch from dinner: the need for comfort. Over a quick lunch, a hard chair isn't a consideration, over dinner it is. We both cleared our plates of food, which is always a good sign, and then discussed desserts. Our waitress recited the dessert menu to us, and home-made mint ice-cream was the choice - one between us. Simple but effective, ice-cream with crushed After Eights through it.

We finished the meal with two good coffees and lingered no more. I know it's not easy to combine a lunch and a dinner format, but if I could have a wish-list for dinner in The Red Onion it would be this: a table covering, softer chairs and softer lighting, proper candles and maybe some matting on the floor to help deaden the sound of passing feet. But all this is with the express purpose of making someone like me linger; if you wanted a quick meal before going elsewhere you'd be well fed. The bill for some very good food and service came to £54.80, to which I added a tip.