No reservations? Don’t despair. Here’s our pick of no reservation restaurants

And so it dawns. Welcome to the maddest week in restaurants, to be followed swiftly by the deadest week. If you woke up this morning a lost soul without a reservation for the coming days don’t despair: we’ve hunted down the best no-reservation places. Most are casual restaurants or wine bars where the food is as good as it gets. But there are some important ground rules for no-res dining. Don’t head out ravenous. A hungry haze won’t enhance your experience.

Smile at the hot and hassled waiter who tells you it’ll be an hour for a table. They have the power in this relationship. In the kindest places they’ll take a name and number and you can wait somewhere more comfortable. A knitting project, a good book or a serious drink habit are all useful accessories. If you are forced to queue, remind yourself this is how the cool kids do it in Shoreditch all the time.

Then in the lull after Christmas an eerie calm descends. High-end dining rooms that heaved with seasonal eaters go dark. Tumbleweeds of tinsel drift over a deserted hinterland. You’ll find restaurant people catching up on their box-sets elbow deep in the Quality Street bucket, gathering strength for the new year’s rush. But thankfully not all of them. Here are the brilliant places that will be open during the lull, when you just can’t face another ham and turkey sandwich for lunch or tea.

One of my favourite new restaurants this year, The Fish Shop on Dublin's Queen Street, is a short trek off the shopping drag. They have just 16 seats and will write down your name and number and release you to one of the nearby pubs to await the call. They open for dinner from 5pm and for lunch on Wednesday, Thursday and Friday from 12pm. The Fish Shop, 6 Queen Street, Smithfield, Dublin 7.

A window seat in Catch 22 is a great place to watch the lit-up Christmas jumpers go by. This fish restaurant just off Grafton Street only takes bookings for tables of five or more, so you should be able to rock up and get a seat. Catch 22, 28 South Anne Street, Dublin 2.

Arrive early (like 11am tomorrow morning) to John Farrell's Super Miss Sue for their new weekend brunch. The casual upstairs restaurant takes bookings now, but also do walk- ins. The brunch menu has their take on Danny Meyer's cacio e pepe eggs. Super Miss Sue, Units 2-3, Drury St Carpark, Dublin 2.

There's not much elbow room in Elbow Lane on Cork city, but they'll take your name and call when your table's ready. The food is grilled and smoked on a brick, iron and tiled fire oven. Elbow Lane, Oliver Plunkett St, Cork. Paul and Máire Flynn's wine bar in The Tannery restaurant in Dungarvan is a walk-in only venue where they serve food from the restaurant kitchen to fill the space between glasses of wine. Croquettes are made with black pudding, smoked bacon or braised veal . My favourite Paul Flynn dish, crab crème brulee, with pickled cucumber and toast is a steal here at €10. The Tannery Wine Bar, open Tuesday to Saturday from 5.30pm, 10 Quay St, Dungarvan, Co Waterford.

Cheese and wine make everything better and the two-year-old comté sliced skin-thin and served drizzled with truffle honey in Belfast's Ox Cave is one of life's truly good things. The wine bar opens at 4pm, so an early arrival should guarantee a seat. Ox Cave, 1 Oxford Street, Belfast.

A freezing dip in icy waves is an optional pre-meal experience if you head to Harry's Shack on Portstewart Beach. Their fish-heavy menu has had wintery delights like slow-cooked venison neck fillet added. You can book, but they also do walk-ins. Harry's Shack, 118 Strand Road, Portstewart, Co Derry.

During the lull The West Restaurant at The Twelve Hotel in Barna will be open from December 28th, along with its gastropub the Pins Bar, which has its own pizzeria, so you can dine posh or opt for pizza in the post-Christmas lull. The Twelve, Barna Village, Galway.

Also in Galway, Jess Murphy's brilliant restaurant Kai will open on December 29th after a revamp. It has a new roof and will undoubtedly continue its menu smarts. Kai Cafe Restaurant, Sea Road, Galway.

Feargal and Fiona O'Donnell reopen The Fatted Calf in Athlone after Christmas on December 30th. They are also open this week on Monday, Tuesday and Wednesday with a special early weekday lunch in the run-up to Christmas, with dinner served from 5.30pm. The Fatted Calf, Church St, Athlone, Co Westmeath.

In Dungarvan, The Tannery reopens on the 28th. In Midleton, Kevin Aherne's Sage restaurant reopens on the 29th. His 12-mile, three-course €44 menu takes ingredients from within a dozen miles and turns them into gorgeous dishes like cured lamb's tongue with sweetbread fritters and John Dory with mussels barley, spinach and purple broccoli. Sage, The Courtyard, Main Street, Midleton, Co Cork.