There's a scene in Dylan Moran and Graham Linehan's Black Books where Bernard Black wants to open a "gourmet restaurant" in his book shop. Posh food comes in little towers, Black tells his sidekick Manny. "You're a cook. You have to commit," he roars, burning Manny with a pot as Manny tries to coax tomato soup into a tower.

Fire Restaurant on Dublin’s Dawson St has a “portobello mushroom tower” as a side dish. Bernard Black eat your heart out. Gourmet or what?

But its arrival is as exciting as a text from the garage offering a discount on my next service. Four flattened mushroom tops filled with a gritty garlicky butter and breadcrumbs lie beside each other on a small side plate. “Portobello?” my inner Dublin taxi driver says sardonically, “More like Ballymun.”

This is about as much of a tower as one of the demolished blocks of flats. The only attempt at height is a clump of pea shoots plumped up as high as they will sit on top of the flat brown disks.

Fire is in the former Supper Room of the Mansion House. The wood-panelled vaulted room has overtones of a Masonic lodge with crests and star-shaped stained glass windows inside circular ones.

A mix of Celtic, Dublin and fire themes is sprinkled through the room with all the subtlety of a St Patrick's Day float. The centrepiece is a set of huge pewter spires, each like a mini version of the O'Connell St one. The wood-fired oven in one corner looks like it was designed by Macnas, copper clad and more swirly Celticky stuff. "Americans would love it," my friend says. But so what? Food doesn't have to tower and rooms don't have to be hip for dinner to be delicious.

There are plenty of good Irish ingredients listed on the menu and they’re cooking with fire. Not everything. Presumably not the French onion soup, which is fine. It’s marked vegetarian but what’s a little beef stock between friends? And it’s a little oversalted, thick enough with gelatinous onions to make a good stab at a tower.

My starter of “wood-fired” Ardsallagh goats’ cheese doesn’t seem to have gained anything in flavour from either wood or fire.

It’s got a coating of pistachio nuts and a round of sweet briochy toast underneath. Its beetroot “compote” isn’t jammy like the name suggests but thin and grainy in a way that will never convert a beetphobe.

There’s a thick clump of micro greens, which I’ve only seen before sprinkled as a garnish. The “honey drizzle” on the bare part of the plate looks like the work of a five-year-old let rip with a supermarket squeezy bottle.

Carol’s steak is the best thing of the night. An 8oz sirloin with a great bang of woodsmoke on the outside, the 28-day aged meat still juicy and bright red inside. Her pont neuf chips are thick as chair legs, fluffy inside and stacked Jenga style.

True to gourmet traditions my sea trout fillet is served in two squat towers. The ground floor of each one is a fried risotto cake of feta and butternut squash. It’s heavy and greasy with all the allure of a wonky doughnut. Then there’s a sweaty clump of samphire which has sandwiched between the risotto cake and a pan-fried piece of trout.

The fish is fine. But a butter-heavy sauce has been ladled over the middle of the plate to take it from heavy to leaden.

We share a “zesty” lemon tart which is as zesty as my mushroom tower was towering. It’s got coconut baked into the base. It’s not a traditional ingredient in a lemon tart and one taste confirms why. Coconut makes for a soggy rather than crisp counterpoint to the lemon filling.

I’ve nothing against an old-school supper room. Dublin needs more of them. But the food here is not the simple hearty cooking I’d love to find. It’s an attempt at posh food with spendy prices (mains are verging on €30 apiece) without any brilliant flavours. The final impression is something as soulless and dated as a flatscreen with a perpetually flickering log fire.

Dinner for two with two glasses of Pinot Grigio and a tea came to €104.90.

THE VERDICT: 5/10 Location great. Food deeply ordinary

Facilities: Fine

Music: Lovely old school jazz

Food provenance: Plenty including cheeses and Slaney Valley lamb

Wheelchair access: Yes