There's more to Scottish food than innards, stodge and deep-fried Mars bars...

It contains the heart, lungs and liver of a farmyard animal and is bound together with stomach lining. Such a mixture might appear in many people's worst nightmares. But the Scottish people have made haggis their national dish.

This Sunday, on Burns Night, Scots all over the world will sit down to honour their national poet with the traditional supper of haggis, along with tatties (mashed potatoes) and neeps (swede). Other nationalities, meanwhile, remain a little baffled by Scottish cuisine, which seems to rely heavily on innards and stodge.

A spate of Scottish culinary modernisers is hoping to put paid to such sentiments. According to the experts, Scottish cuisine is in rude health. This week, it was announced that Michelin stars north of the border are at their most numerous ever and even sales of haggis are up across the UK, at Marks & Spencer, Asda, Waitrose and Sainsbury's.

"I think the quality of the produce we have is unrivalled," says James Thomson, owner of the Witchery by the Castle, one of Edinburgh's most celebrated restaurants. "We have fantastic beef, lamb, venison and salmon, probably because we have so much land and unspoilt, good, local produce, which I think we do best when served unadulterated and cooked simply."

Scotland's diet is normally a major cause of concern in the country, being high in fat, salt and sugar, and low in fruit and vegetables. Bad restaurant experiences north of the border are ten-a-penny. The Scots' reliance on the deep-fat fryer has become something of a joke among other nations. Rab C Nesbitt was known to like deep-fried Mars Bars. A 2004 survey of 300 Scottish fast-food restaurants found a quarter serving deep-fried 420-calorie chocolate bars alongside fish and chips. Similarly, dishes such as haggis have invited scorn. The meal is prepared by washing a sheep's stomach in cold water and stuffing it with oatmeal and the animal's innards. "We do serve offal in my restaurants, but while I like haggis, it's not something I've served, as some of my customers might not like it," says celebrity chef Tom Aikens.

But Scottish culinary experts believe the nation has been unfairly singled out for a trend reflected by many countries. A government survey, published this month, showed there had been some progress in improving the nation's health. The Scots think there is plenty to feel positive about.

"I think the problem with some Scottish cuisine is that choice has become very narrow in some areas," says Scottish chef Sue Lawrence, author of A Cook's Tour of Scotland (Headline, £14.99). "But that is a trend which is reflected everywhere, and is down to an increase in processed foods. You can put that down to people's laziness. Prior to microwave meals' rise in popularity, we ate in one of the healthiest of ways in Europe, relying on simple dishes based on meat and potatoes. Soups, stews and home baking were our strength. Our baking stuck to the basics, producing really delicious scones, pies and cakes."

Furthermore, the likes of Lawrence think that such a blinkered view of Scotland is overlooking its wealth of present-day delicacies. "A well-made butcher's Scotch pie is the most delicious thing," she continues. "The best of those we have are sublime and it is just a question of choosing the best." And then there are the ingredients. "Before the BSE crisis, even Italy and France used Scottish beef as opposed to English or Irish meat. All of our mussels and crabs would be sent to Paris or Madrid, where they would be appreciated. It has taken the Scottish a long time to take local ingredients and to appreciate them for ourselves. Which is great."

This week, the number of Scottish eateries with the coveted Michelin stars rose to 14. The Albannach, near Lochinver in the west Highlands, Boath House in Nairn, and Sangster's in Elie, entered the guide for the first time. The number of such entries has been hailed by tourism leaders as a useful injection of trust in an industry riddled with concerns about the economic downturn. "[I am] absolutely delighted to get a Michelin star and have been on cloud nine since I heard," said Lesley Crossfield, who runs the Albannach hotel with her partner, Colin Craig.

Martin Wishart, who owns Restaurant Martin Wishart, the first restaurant to be given a Michelin star in Scotland (in 2001), cites scallops, Shetland lamb, Finnan haddock, berry fruit and beef and game among his favourite local produce. "Scallops from west Scotland are consistent, very firm, sweet, and very clean. Shetland lamb is natural, very tender, very consistent and has a nice taste of peat." He also praises Finnan haddock for its creamy taste, and Scottish berries, which are only available for certain months of the year, but have a specific, "enjoyable" sweetness. He also says the country has good weather for raising livestock.

"Whenever I am in London, I see Scottish food on the menu and advertised as beef and lamb and shellfish as coming from Scotland," Thomson agrees. "I think Scotland has always been seen as high-quality larder. I haven't seen any negative comments."

Meanwhile, it is not just Scots who come to dine on the haggis that is served year-round at Albannach, the Scottish restaurant in central London. "It's not just visiting Scots who come to enjoy our haggis," says Neil Preston, head of marketing at Albannach. "We have young professionals, the West End crowd and business people of all nationalities coming down, with a few sports personalities thrown in. Haggis has a bad name, but it's generally unjustified – if it's done properly. "

Now there is just the small question of Burns Night to worry about. Lawrence thinks the best haggis is nicely moist but lacks a greasy aftertaste. It should be able to be served on its own, or be accompanied by something such as turnips, not needing gravy or sauce. It should also be nicely spiced without being too "in your face", and vaunt a consistent texture, which is derived from the quality of the oatmeal employed. "A good haggis is better than white truffles or caviar," she concludes. "It wouldn't be right not to have haggis at some stage, because it is one of our basic national sources of pride," adds Roger Coutharld, manager of Stack Polly, another popular restaurant in central Edinburgh. "There's something warming about it, like it's nursery food or something."

The verdict: Haggis virgins tuck in

We offered some "haggis wi' bashit neeps and champit tatties" (haggis with mashed turnips and potatoes), prepared by the Scottish restaurant Albannach in Trafalgar Square, London, to passers-by. Here's their verdict:

Paddy O'meara

23, student, Dublin

"Ah, it's good! Really good, actually, it's not too dense. An odd texture, though, it's like lots of little balls. There's some mash here, too, and I suppose all together it just tastes a bit like shepherd's pie. It also slightly reminds me of black pudding. I'd definitely give it a shot again."

Teri O'Donnell-Johnson

55, college teacher, San Francisco

"A line from a Mike Myers film springs to mind: 'All traditional Scottish food is based on a dare'. This tastes like barley or oatmeal; there's almost a slight aftertaste of Worcestershire sauce. It's unusual, but really, really good. The texture is quite fine – it's almost like it's made up of lots of little balls. It's blended very nicely with a pleasant aftertaste. It really is very good."

Andrew Lynch

22, salesman, Dublin

"It's really nice. If I had to compare it to another type of meat, I'd just say it tasted like ground minced beef. Honestly, I'm rather surprised, it's not bad. I really thought it would be tasteless and chewy but it isn't."

Rita Bellamy-James

Over 50, lawyer, London

"It's very rich, with a good, thick texture – I like it like this. You can have two different sorts of haggis, one is very smooth and the other one is slightly chunkier. I prefer it when it's not too smooth. The haggis has a nice afterglow, with a slight spiciness which is very attractive. I do rather like haggis, and I like the slight peppery taste to this dish. The gravy is good, but perhaps best when it's a little runnier, and of course you should have it with a tot of whisky, just a wee nip. It's an excellent combination of flavours."

Mike Johnson

54, business owner, San Francisco

"I've never tried haggis, so this should be quite interesting... oh, it is! Actually, it's really great. It's a bit like mincemeat but with a strong savoury flavour. Although it's in a similar style to hamburger meat, it's not quite as cemented together, it just crumbles on your mouth. This sauce is really good, too."

Alexis Ashman

22, trainee journalist, north-west London

"It is actually really rather nice, and I'm pleasantly surprised. It appears to be made up of tiny little brown and white balls, some of which seem to have a slight gristle-like texture, which I suppose gives it a slightly chewy, slightly rough texture. There's quite a strong flavour of spices which give it an almost smoky aftertaste. It is definitely not as offal as I thought..."