Whatever your preconceptions about Mexican food, if you've never eaten in Mexico they will almost certainly be wrong. It bears very little resemblance to the concoctions served in "Mexican" restaurants or fast-food joints in other parts of the world - certainly you won't find chile con carne outside the tourist spots of Acapulco. Nor, as a rule, is it especially spicy; indeed, a more common complaint from visitors is that after a while it all seems rather bland

Basic meals are served at restaurantes , but you can get breakfast, snacks and often full meals at cafés too; there are take-out and fast-food places serving sandwiches, tortas (filled rolls) and tacos (tortillas folded over with a filling), as well as more international-style food; there are establishments called jugerías (look for signs saying "Jugos y Licuados") serving nothing but wonderful juices ( jugos ), licuados (fruit blended with water or milk) and fruit salads; and there are street stalls dishing out everything from tacos to orange juice to ready-made crisp vegetable salads sprinkled with chile-salt and lime. Just about every market in the country has a cooked-food section, too, and these are invariably the cheapest places to eat, if not always in the most enticing surroundings. In the big cities and resorts, of course, there are international restaurants too - pizza and Chinese food are ubiquitous. Argentinian restaurants are the places to go for well-cooked, good-quality steaks.

When you're travelling, as often as not the food will come to you; at every stop people clamber onto buses and trains (especially second-class ones) with baskets of home-made foods, local specialities, cold drinks or jugs of coffee. You'll find wonderful things this way that you won't come across in restaurants, but they should be treated with caution, and with an eye to hygien

The basic Mexican diet is essentially one of corn ( maíz ) and its products, supplemented by beans and chiles . These three things appear in an almost infinite variety of guises. Some dishes are hot (ask ¿es picante? ), but on the whole you add your own seasoning from the bowls of home-made chile sauce on the table - these are often surprisingly mild, but they can be fiery and should always be approached with caution.

There are at least a hundred different types of chile , fresh or dried, in colours ranging from pale green to almost black, and all sorts of different sizes (large, mild ones are often stuffed with meat or cheese and rice to make chiles rellenos ). Each has a distinct flavour and by no means all are hot (which is why we don't use the English term "chilli" for them), although the most common, chiles jalapeños, small and either green or red, certainly are. You'll always find a chile sauce ( salsa ) on the table when you eat, and in any decent restaurant it will be home-made; no two are quite alike. Chile is also the basic ingredient of more complex cooked sauces, notably mole, an extraordinary mixture of chocolate, chile, and fifty or so other ingredients traditionally served with turkey or chicken (the classic mole poblano ), but also sometimes with enchiladas (rolled, filled tortillas baked in sauce). Another speciality to look out for is chiles en nogada , a bizarre combination of stuffed green peppers covered in a white sauce made of walnuts and cream cheese or sour cream, topped with red pomegranate: the colours reflect the national flag and it's served especially in September around Independence Day, which is also when the walnuts are fresh.

Beans ( frijoles ), an invariable accompaniment to egg dishes - and with almost everything else too - are of the pinto or kidney variety and are almost always served refritos , ie boiled up, mashed, and "refried" (though actually this is the first time they're fried). They're even better if you can get them whole in some kind of country-style soup or stew, often with pork or bacon, for example frijoles charros .

Corn, in some form or another, features in virtually everything. In its natural state it is known as elote and you can find it roasted on the cob at street stalls or in soups and stews such as pozole (with meat). Far more often, though, it is ground into flour for tortillas , flat maize pancakes of which you will get a stack to accompany your meal in any cheap Mexican restaurant (in more expensive or touristy places you'll get bread rolls, bolillos). Tortillas can also be made of wheatflour ( de harina ), which may be preferable to outsiders' tastes, but these are rare except in the north.

Tortillas form the basis of many specifically Mexican dishes, often described as antojitos (appetizers, light courses) on menus. Simplest of these are tacos , tortillas filled with almost anything, from beef and chicken to green vegetables, and then fried (they're usually still soft, not at all like the baked taco shells you may have had at home). With cheese, either or alone or in addition to other fillings, they are called quesadillas . Enchiladas are rolled, filled tortillas covered in chile sauce and baked; enchiladas suizas are filled with chicken and have sour cream over them. Tostadas are flat tortillas toasted crisp and piled with ingredients - usually meat, salad vegetables and cheese (smaller bite-size versions are known as sopes). Tortillas torn up and cooked together with meat and (usually hot) sauce are called chilaquiles : this is a traditional way of using up leftovers. Especially in the north, you'll also come across burritos (large wheatflour tortillas, stuffed with anything, but usually beef and potatoes or beans) and gorditas (delicious small, fat, corn tortillas, sliced open, stuffed and baked or fried). Also short and fat are tlacoyos , tortillas made with a stuffing of mashed beans, often using blue cornflour, which gives them a rather bizarre colour.

Cornflour, too, is the basis of tamales - found predominantly in central and southern Mexico - which are a sort of cornmeal pudding, stuffed, flavoured, and steamed in corn or banana leaves. They can be either savoury, with additions like prawn or elote, or sweet when made with something like coconut.

Except in the north, meat is not especially good - beef in particular is usually thin and tough; pork, kid and occasionally lamb are better. If the menu doesn't specify what kind of meat it is, it's usually pork - even bistec can be pork unless it specifies bistec de res . For thick American-style steaks, look for a sign saying "Carnes Hereford" or for a "New York Cut" description (only in expensive places or in the north). Seafood is almost always fresh and delicious, especially the spicy prawn or octopus cocktails which you find in most coastal areas ( coctel or campechana de camaron/pulpo ), but beware of eating uncooked shellfish. Eggs - in country areas genuinely free-range and flavoursome - feature on every menu as the most basic of meals, and at some time you must try the classic Mexican combinations of huevos rancheros or huevos a la mexicana

Vegetarians can eat well in Mexico, although it does take caution to avoid meat altogether. Many Mexican dishes are naturally meat-free and there are always fabulous fruits and vegetables available. Most restaurants serve vegetable soups and rice, and items like quesadillas, chiles rellenos, and even tacos and enchiladas often come with non-meat fillings. Another possibility is queso fundido , simply (and literally) melted cheese, served with tortillas and salsa. Eggs, too, are served anywhere at any time, and many jugerías serve huge mixed salads to which grains and nuts can be added.

However, do bear in mind that vegetarianism, though growing, is not particularly common, and a simple cheese and chile dish may have some meat added to "improve" it. Worse, most of the fat used for frying is animal fat (usually lard), so that even something as unadorned as refried beans may not be strictly vegetarian (especially as a bone or some stock may have been added to the water the beans were originally boiled in). Even so-called vegetarian restaurants, which are increasingly common and can be found in all the big cities, often include chicken on the menu. You may well have better luck in pizza places and Chinese or other ethnic restaurants

Since so much Mexican food is simple, and endlessly repeated in restaurant after restaurant, one way to tell the places apart - and a vital guide to the quality of the establishment - is by their salsa . You'll always get at least one bowl or bottle per table, and sometimes as many as four to choose from. A couple of these will be proprietary brands (Tabasco-like, usually with great, exotic labels and invariably muy picante) but there should always be at least one home-made concoction. Increasingly this is raw , California-style salsa: tomato, onion, chile and cilantro (coriander leaves) finely chopped together. More common, though, are the traditional cooked salsas, either green or red, and almost always relatively mild (though start eating with caution). The recipes are - of course - closely guarded secrets, but again the basic ingredients are tomato (the green Mexican tomato in green versions), onion and one or more of the hundreds of varieties of chile.