The wealthier the hood, the richer the pickings, right? At least that’s the hope on a Sunday evening after a walk in the wind on Dún Laoghaire’s wilder pier, a wind which has blown us back to Monkstown for dinner.

The first signs are good in Le Plancha, which has moved from Blackrock to the top end of Monkstown Crescent, a hotchpotch of brick mews buildings that has become Monkstown’s restaurant strip. Le Plancha is a warm smart place where things smell of nice goings-on in the kitchen.

The restaurant is upstairs in a room that feels like an airy attic. There are small sash windows on three sides. We pick a table by one of these, the freshly glossed window sill giving us a space to unholster some of life’s paraphernalia: glasses, phone, hang-ups about the impossibility of finding good restaurant food on a Sunday night.

Cooking a la plancha means using a cast-iron plate heated on a flame. In skilled hands it means the best marriage of heat and food, caramelising the outside of meat, fish or vegetables while keeping everything luscious inside.

The restaurant name suggests something rustic and Spanish (or is it Frenchish with that jarring “le” instead of “la”?), but it’s a “bistroville” kind of menu. I’m not sure how the “famous chicken wings” advertised on the back of the toilet doors fit into a flame-meets-iron school of cooking.

I have a lot of time for hard-working neighbourhood restaurants, keeping the burners lit seven days a week, serving brunch through early bird to after dark.

And at the start it looks like this is another solid offering, nothing to thrill or disappoint. Until it gets disappointing. Weirdly and inexplicably disappointing.

Mussels are good, served in a sauce with clumps of juicy tomato clinging to the occasional, shell-like, delicious flotsam.

Across the table there are shoestring calamari, crisply fried. They are presented on plate decorated with concentric circles of chilli sauce like a Hitchcock tribute. Each clump of calamari has been sat on to a puddle of pickled fennel and fresh radish slices. I would forgive the fussiness of the plate if the chilli didn’t taste like bad jam and the fennel wasn’t watery.

A “rare breed” pork chop is a nicely thick slab of pig but not as juicy inside as its thickness promises. It is topped with a red onion marmalade made with so much star anise that it has seeped its oddly mismatched flavour into the meat. There are good intentions here, and the plate comes with chunks of creamy garlic potato.

However, my special is where it all goes wrong. Black sole on the bone with saffron potatoes is sullen and rubbery, cooked to the point where it’s tricky to avoid the pin cushion in the mouth moment as bone and flesh meld together. Vegetables are fine, matchstick carrots and broccoli.

There is no colour or flavour of saffron on the potatoes. They sit like waxy marbles in a pool of celeriac puree, which is probably the best thing on the plate, although it’s a mystery why it’s there. A bowl of creamy spinach brings this part of the meal to €30.

And so on to desserts, which at €8 a pop must surely involve the soothing kind of cooking needed to get us back on track. How wrong can you get crumble and creme brulee? Plenty it turns out.

Call your creme brulee a lemon curd version. Then spoon a dollop of lemon curd on top of a regular creme brulee making it look like split custard oozing its yellowness out through the sugar. Both elements taste fine, but just not together.

Next stew apples and leathery blackberries until they’re almost jam and sprinkle them with a pale crumble topping that looks like bashed-up shortbread biscuits and has tooth-cracking nuggets of sugar in it.

The final one way ticket to wrongsville is the small silver jug of stone cold custard served on the side. It’s a tribute to bad school dinners.

And the bill is €90, without a drop of booze. A couple of glasses would have taken us into three figures. I can’t figure this place out. Service is good, it’s a lovely room and some dishes are getting it nearly right.

Maybe it’s the timing, some kind of Sunday lull. The quest for a good restaurant meal on this, the trickiest night of the week, continues.

Dinner for two with sparkling water and a mint tea came to €90.

LE PLANCHA, 1a The Crescent, Monkstown, Co Dublin. Tel: 01-2845860

Music: Jazz

Food provenance: Limited. Thornhill Duck named

Facilities: Fine

Vegetarian options: Limited

Wheelchair access: No

Verdict: 5½/10. A nice new home but the food needs work.

Second helping . . .

Log fires, warm scarves and baked Mont D’Or cheese are all consolations of winter. The soft Alpine cheese is made from winter milk when the cows come off the mountain and are fed on hay instead of summer grass. So Mont D’Or is seasonal, only available in the colder months.

Baking a Mont D’Or in its spruce box is the world’s easiest ta-da dish to round off a meal. Surprisingly few restaurants offer it. Until now.

We had one in Fallon & Byrne’s downstairs wine bar at a gathering with friends. It’s not cheap – at €29 it’s more than twice the cost of baking one at home – but it’s a lovely convivial thing to gather a group around to share its sweet creamy ooze.

Fallon & Byrne Wine Bar, Exchequer St, Dublin 2