The meal everyone has been waiting for all year is set in stone on Christmas Day, but why doesn't tradition dictate what we eat on the eve of turkey day?

'Twas the night before Christmas and all through the house, people were eating baked ham, burritos, fish pie and tikka masala. This is Britain: where Christmas dinner is all mapped out, but Christmas Eve is a culinary free-for-all. I have relatives for whom 24 December isn't complete without steak and chips. Others insist on Indian takeaway, while for years my friends and I celebrated at a Tex-Mex restaurant (because nothing says Christmas like a chimichanga).

In many European countries the Eve is commemorated with a gut-busting feast. Yet in Britain, the 24th lacks a universal tradition, leaving us free to create our own rituals. There are recurring themes, but is there a reason why we don't we have a national Christmas Eve dish on a par with Christmas dinner?

Food historian Catherine Brown says it's because "festive eating habits in the past have often been dictated by religion. When Christmas was banned in Scotland after the Reformation, Presbyterian ministers visited their flock to check they had no festive foods in the house. Christmas wasn't a public holiday in Scotland until 1958, so there's no long-established history of festive eating on Christmas Eve in either my parents' or grandparents' memories. In England, the Puritans also banned the celebration of Christ's Mass. But, unlike Scotland, Christmas traditions revived after the monarchy was restored."

One of the more popular Christmas Eve dishes is fish, particularly fish pie. "This is a Catholic tradition related to the Feast of the Seven Fishes. Some Catholics still include seven different fishes in the meal – not difficult if you're making a pie," says Brown. Christmas Eve was traditionally part of the advent fast period, and during this time fish was eaten widely, a tradition that carried on even after the Reformation: "Fish days were regularly promulgated by monarchs including the Stuarts, to stimulate the British fish trade," says food historian Annie Gray.

It's hard to know how many Brits, Catholic or otherwise, still eat fish on Christmas Eve because when it comes to Christmas we are a myopic bunch – what's traditional in our own house becomes the only tradition. But food writer Felicity Cloake, for one, is a fan. "We always, always have fish: either pie or a big piece of salmon. It's nice to give yourself a break before the meatfest to come."

Ham is also popular. "It's an old tradition linked to the Martinmas slaughter of the animals people couldn't afford to feed during the winter. The best joints - the hams - were eaten at the feasting dinner," says Brown. For a contemporary take, the goddess Lawson suggests ginger-glazed ham for Christmas Eve in her recipe book Nigella Christmas.

Christmas Eve is also a time for dishes that reflect our diverse backgrounds. Spiced beef is on the menu at Irish blogger and author Niamh Shields's house: "It's like corned beef but with spices and is a grand Cork Christmas tradition. It goes back to the spice trade. Traders from Asia would travel to Cork and trade spices for butter."

Few go to town on Christmas Eve feasts like the Italians. "Our family has always prepared a multi-course fish-based dinner for about 24 people," says chef Massimo Bottura. In the Caldesi household, chefs Katie and Giancarlo have created an Anglo-Italian ritual: leaving out port and panettone for St Nick. Meanwhile, like the Catholics, half-Italian cook Laura Santtini nods to her roots with a fish pie: "Fish is meant to bring good luck for the coming year, so I make it with a big pinch of Italian guilt for fear of breaking with tradition."

Like the Italians, Scandinavians also hold their main feast on the 24th. The Swedes serve sumptuous julbord. "For Christmas Eve dinner, we have a table laden with pickles and preserves. Pickled herring is the most important component, then boiled eggs and Löjrom, says Swedish chef Niklas Ekstedt. Half-Danish chef Anna Hansen still celebrates with a feast consisting of "braised red cabbage, brown potatoes (baby potatoes blanched and then finished in butter and sugar), boiled new potatoes, roast pork and gravy."

Gravlax is also popular among non-Scandis. The Caldesis pair it with champagne, while Australian food writer Bill Granger says: "When I was growing up, we didn't really have any Christmas Eve traditions, but as soon as I had my children, we felt like we needed our own. I get some gravlax to make smoked-salmon blinis and do a couple of big salads."

So perhaps our lack of Christmas Eve culinary tradition doesn't matter – it just leaves us free to cherry-pick the best continental rituals and make up our own. Start this season, and in a few years it'll seem as much a part of the day as sobbing over The Snowman or putting out carrots for Rudolph. Whatever you eat on Christmas Eve, have a merry one.