I'd been hearing about Harry's for some time before I made it across the threshold a few weeks back. It has a reputation for passionate sourcing of the best of ingredients from the Inishowen peninsula on which it is located. Restaurants such as Harry's – situated somewhere we Dublin-based hacks consider being off the beaten track – tend not to get the attention that they deserve. Beyond-the-pale restaurateurs grumble with cause, but the reality of budgetary constraints means that it's not the class of a trip to be made on the off-chance. Happily, a sojourn in nearby Dungiven to check out the glamping at Ash Park, a Featherdown Farm (see Travel, page 40), afforded us the opportunity to make amends and to drop into Harry's for a late lunch on Saturday afternoon.

Harry's lies just across the border into Donegal from Derry, and there's a 'no man's land' feel to the stretch of road on which it's situated. I'm assuming that Harry's was a straightforward pub in a former life, but that the success of the food offering has skewed the operation so that it is more restaurant than bar these days, although there is a bar menu too. There's a touch of roadhouse about it. The dining room is a large, smart space on several levels – about half full when we arrived, with most of the other parties family groups like ours. Harry's has a reputation for treating children as well as it does its older customers. While on this occasion we might have preferred fewer of them in such close proximity, a few years back we'd have been delighted to find ourselves in a room such as this, well-equipped with high chairs and with so little fuss being made about either spills or decibels.

There were six of us – for food purposes five adults and one child – and between us we covered a good cross-section of Harry's lunchtime offering. Fresh Seafood Chowder and a Greencastle Seafood and Crab Salad (incorporating some heavily dill-marinated, salty and rather good smoked salmon) were both exemplary and generous, served with terrific home-made brown bread. Both were priced at €6. (That's not a typo.) A small Smoked Chicken Caesar with Organic Salad was also €6. It wasn't wholly authentic but it was, said Milo, wholly delicious – "with lots of pancetta and not too much lettuce". A special starter of Squid Tagliatelle in a Tomato Sauce was tasty enough and a selection of patés included a great chicken liver version and a not-so-exciting smoked ham variant. These starters were priced at €5 each.

Harry's has an on-site meat-hanging room in which it ages its steaks. Unfortunately, the big bone-in rib-eye for two that is a house specialty is not on offer at lunchtime – we'll have to go back for that experience – but a children's Minute Steak (€10), an 8oz Sirloin (€15) and a Home-made Burger with Bacon and Cheese (€9) were all excellent, as were the 'chip-shop chips' that accompanied them. These are not earth-shattering, change-the-world dishes – although the meat is of unusually high quality – but they are the kind of thing that a majority of punters wants to find on a menu and there's no arguing with that. A butterflied Moroccan Chicken Breast (€9) marinated in vibrant citrus, herbs and spices sang with flavour.

On the day of our visit, though, it was the fish choices that were the most interesting options on the lunch menu. A fine portion of hake came with a simple lemon butter sauce, while crispy skinned mackerel fillets were served with beetroot and apple. Both came on a bed of spinach. The fish was spanking fresh, and in Dublin these dishes would have cost at least double the €9 that Harry's charged for them.

Between the six of us, we shared one of each of three puddings on offer. We loved the Rhubarb and White Chocolate Cheesecake with Pistachio Cream and the Chocolate Mousse Cake on a biscuit base. The Knickerbocker Glory looked fabulously decadent but had too much banana flavour going on for our taste. The puddings are all priced at €4.

Our total bill, with three glasses of wine, six diet cokes and three coffees, came to €136 before service. For six people. Extraordinary value.

Harry's, Bridgend, Inishowen, Co Donegal. Tel: (074) 9368444

★★★★