Restaurateurs tend to pick a niche and stick to it. Yes there are renegade chefs handing back their stars and going all bistronomie occasionally. But typically restaurant concepts are dreamt up, business plans agreed, menus laminated and then it’s off to plough a straight furrow with an unblinking gaze on the horizon straight ahead. Until the next generation comes along, throws all those ideas out and starts over.

So when I hear that a casual fish place I really liked the first time round has reinvented itself with a tasting menu, it’s time to make a return visit. The Fish Shop on Dublin’s Queen Street is now a seafood restaurant with a menu driven by whatever is freshest off the boats. They’ve opened a wine bar and fish and chip shop on Benburb Street to do what they started out doing in Queen Street. And, with the lines redrawn, they have created a little thing of beauty: the casual tasting menu.

Bentwood chairs have replaced the old school chairs and the other touch I love is the clean white linen napkins, ironed but still soft from use and laundering. They have literally taken the starch out of the sit-up-straight dining experience.

The tasting menu idea is all about showing off. This is refreshingly unshowy. It’s not so much a “look what the chef can do” as a look what our seas and fields can do, even in the depths of winter. Tonight’s menu is written in black marker on the white-tiled wall. At the end we get a copy on paper to take home. There are three types of fish up ahead, four if you include the oysters we get to start. Van Morrison is singing on the sound system. The tasting menu is €35 a head. Wouldn’t it be great if restaurants were like this all the time?

Smart wine list

There’s a short, smart wine list and I’m pushing the boat out with a glass of the Aligoté, a big-hearted Burgundy that seems to work with every dish. Across the table he’s having “communion wine” in the shape of a glass of Manzanilla, before moving to the Picpoul.

And so it begins with lightly tempura-ed oysters in their shells, with a splodge of seaweed mayonnaise underneath and sweetly pickled shallots on top. Squid is a scroll of white meat browned on top and sitting like a pool noodle on a silken Jerusalem artichoke soup, which has a tang of apples thanks to a dollop or two of cider. Hazelnuts have been toasted and turned to dust to sprinkle over the whole sweetly delicious bowl. Then there’s mackerel. It’s cured, according to the menu, and also blow-torched, so the skin has blistered and blackened crisper than a bag of Tayto. There is cool crème fraîche and a range of vegetables, pickled carrots and roasted beets, sweet and earthy all at once.

The closest we get to a main dish is a generous fillet of wood-roasted brill. The perfect white fish sits on top of cubes of celeriac roasted till they’re chewy on the outside. There’s black kale here too and the whole lot is drizzled with a herbed brown butter, as close to savoury caramel as is decently allowed. The person who told me about this tasting menu mentioned this lightness of touch, the lack of creamy sauces poured like lagging jackets over fish. It’s just the pure flavours of the sea, he said.

Dessert looks modest, but is a real stunner. It’s a chewy, biscuity almond cake made from scratch with good ingredients shortly before it’s served. Like the oven-fresh brown bread we had earlier, there’s a talented baker at work here. The cake is topped with two lovely things that promise brightness and colour to come in the spring. The first is a quenelle of buttermilk ice cream, all lactic tang and creaminess. The second is some small sticks of bright pink rhubarb. So the whole lot brings you from satisfying sweetness through tang and up to tart in three delicious steps.

The Fish Shop has grown up and is swimming with the bigger fish now, with its simple, pared-down menu. Sourcing the ingredients of the moment and cooking them brilliantly is an idea that gets talked about a lot, mostly by people who aren’t truly doing it. In this spartan but warm room where diners look out on to a darkened street and the passing Luas, they’re doing it with a whole heart. The prices are mid-range, the food is several notches higher. Go now while you can still get a table.

Dinner for two with a sherry and three glasses of wine came to €102.40.

Fish Shop, 6 Queen Street, Dublin 1

Tel: 01-4308594

Facilities: Good, generously sized

Wheelchair access: Yes

Food provenance: McNally family farm vegetables, fish from SSI and Kish

Music: Enlightened, thanks to Van and several others.

Vegetarian options: None. It's a seafood restaurant.

THE VERDICT: 8.5/10 A fish lover's dream come true