Hands up who wants to be called granny. Not the woman whose son is sitting next to us at the counter in Howth’s newest restaurant, he tells one of its owners, Jess D’Arcy. His mother is in no rush to relinquish herself to notions of cardigans and Complan or, heaven forbid, glamorous granny.

Until now I’ve been pronouncing the name of this restaurant all wrong. Maymo, I’ve been saying, thinking Norse instead of north Dublin. Mamó is the Irish pet word for grandmother. It’s Ma, like Baa, big mother, two comfort syllables that murmur in the back of the mouth, where all the best words start.

If you’re expecting chintz and granny-style nostalgia, Mamó is a classier dame than that. The restaurant is the work of the husband-and-wife team of D’Arcy and the chef Killian Durkin.

The room used to be a wine bar, owned by an accountant, who is still upstairs. Now it’s a reason to hop on a Dart to Howth and make-believe this is your neighbourhood for the evening.

We walk from the station, take a wrong turn and end up on the upper road, before a local takes time out of his day to help us find where we need to be. It’s that kind of place.

So we walk down the steep steps, so typical of seaside villages, to the white painted building with its name in minimal lettering on the side. Outside there are tables and chairs with warm blankets for outdoor lunches. Inside is the smell of buttery fish and the hum of happy conversation.

They’re only recently open but tables have been snaffled quickly, so we book a slot on the stools at the counter.

Coats disappear, bags are hung on the hooks that tell you someone’s thought about your needs. It’s a white painted finish here, with wooden shelves and wine bottles.

The name may not be Scandi but the first snack is. It’s soused herring, with candied lemon for a sour twist on the sweetly pickled fish and some nutty lentils to net it all down. Being a shell’s throw from the harbour means Mamó can serve a ceviche of the day, depending on what’s in the fish boxes that day.

Today it’s monkfish, juicy slices of that precious fish “cooked” with the citrus of orange, a little soy and some chilli for spice kicks, with sweet cubes of pickled cucumber where the direction has been sweetness rather than gherkin. It’s a beautiful plate of food.

But the bowl of the night is the clams. They’re juicy fat babies with purple tinged shells that have fanned open in a brief cooking and then been doused with lime juice, beads of good olive oil and petals of garlic. The happiness doesn’t finish when the clams are wolfed. There’s a sweet garlicky zesty broth that’s got the sourdough’s name written all over it.

The bread comes with vadouvan butter, a whipped airy serving that’s been mixed with nutty pan-fried spices. It’s a marriage of French-inspired fancy butter with masala blends of roasted and ground spices, giving us the bread and butter version of curry and carbs chipper pleasure.

Carol has the lamb. It’s Comeragh Mountain lamb and the meat has been cooked so slowly that the fat has rendered to syrup that becomes the perfect medium for elevated levels of gorgeous meat flavour.

I get a pillow of brill, fried in butter, and it is as fresh as you’d expect in this salt-steeped place. It comes with tiny trees of cauliflower, vinegar pops of capers and fingernail-sized brown shrimp.

D’Arcy explains that the Howth honey they use in their dessert is a source of vehement local pride, so they’ve got just one serving left. The honey is almost peppery thanks to the heathery, salty diet of the local bees.

They make a baked cream tart with it, topped with candied lemon and blackberries. There’s a biscuity base thinner than a credit card and it’s served with sea salt ice-cream.

It’s a simple lesson from a young couple who are excited by their larder of ingredients in this lovely spot, but also aware that the simpler the ideas on the plate the more they can turn seaside village terroir into spoon licking pleasure.

My consolation dessert is no dud either. There’s a thick chocolate ganache that has been made with lemon juice so the bitter chocolate melds with a citrus tang. Sweet kicks come in the melted marshmallow form of Italian meringue and then there’s tang from blousy blueberries to add a third leg to this dish.

Mamó is a breath of fresh sea air, a delicious alliance of place and people. “Yer in yer granny’s now,” was the saying in my childhood. It was typically used when we were nowhere near either granny. Instead it meant the casting of a wise and kindly eye on any indulgences. Mamó is an indulgence, not cheap, but worth every cent. Go indulge. Yer in yer Mamó’s now.

Dinner for two with (excellent) kombucha, a glass of wine and sparkling water came to €112.25

• Verdict A clever kind restaurant that manages to be both fresh and comfortingly familiar
• Facilities Ship's galley slim but nice
• Food provenance Comeragh Mountain Lamb, Howth Honey and Durrus among the producers named
• Music Lovely
• Vegetarian options: Limited
• Wheelchair access ★★★★☆ Room is accessible but tight for space, and there's a wheelchair toilet (marked private).