Recently a friend landed in Calcutta, arriving in a high good mood. "I have just been quaffing the best gol-gappas in Delhi! I tell you they're the best!" Like any true Calcuttan, my phuchka-pride swelled up and cracked open. "Nonsense! They can't be anywhere near as good as the ones my local guy sells down the road!" A brief argument ensued, a verbal altercation that ended exactly as we both intended it to - we agreed to walk down the road to taste-test my local phuchkawallah's product. At the phuchka station we both took up our stances, my friend standing normally, holding her leaf-cup politely, like the well-brought-up Delhi-ite she is, and myself in a pose reminiscent of the great K. Srikkanth at the crease, legs far apart, body leaning forward, but as if the phuchkawallah was at silly point, and with my leaf-cup thrust out. Presently, the holed and armed sphericals began landing in our cups at speed. My friend soon adjusted her stance to avoid the phuchka water sloshing out of her cup and I began to laugh with the nastiness only found in Calcuttans exposing unsuspecting outsiders to Cal phuchkas for the first time. "Why are they so thin?" My friend complained, "I can hardly get them into my mouth before they disintegrate! The stuffing keeps falling out!" Between expertly crunched mouthfuls I explained to her that sitting at a table in Green Park or Bengali Market and gently eating the rhino-skinned, so-called gol-gappas did not a phuchka-gourmand make. "This is the real thing. It's supposed to be thin. And you're supposed to eat it in... well, in a phuchka-quick moment!" My visitor remained unconvinced and unimpressed: the things were not only too fragile - both the Delhi varieties, normal and suji, held their load better - but also too sour and jhaal, lacking the sweet balancing tang of imli ki chutney, and besides, the potatoes in Calcutta were cooked to an over-spiced mush whereas in Delhi the alu was simply boiled, but boiled perfectly.

Later, I referred our quarrel to a fellow Gujarati friend, unlike me someone who wasn't born and brought up in phuchka-ville but in that other place on the other coast. "What kind of Gujju are you?" He sneered. "What are all these gol-gappa and phuchka pretensions? It's paani- puri. It was born in Bombay. Invented by Gujjus. 'We are the authentic only' as they say here, and we have the best, original paani-puri, bas!" Much as I hated to give any quarter to anything in Vadaa-pau-ville, and even as I was missing the suji puris served by a certain gol-gappa dispenser in Mukherjee Nagar in north Chhola-bhatura-pur, I remembered the echt-Gujarati paani-puri parties of my childhood and felt a twinge - the guy had a point, the balance between chilli, sour and sweet, the complexity and variety of the stuffing masalas, the texture of the puris themselves... aah.

A few days after this, I found myself playing a return match in Delhi, eating gol-g's at Bengali Market, satisfying my suji-puri urge. It was then that I realized the truth: the best phuchka/gol-gappa/paani-puri is the one you are just about to insert into your cavernously open mouth. Unless of course you happen to be in one of those recent chains that have opened in London, their names woven with words such as 'spice' and 'masala' to connote some coolly hot South Asian chilliness, their gol-puri-phuchkas a travesty of the real things, made all the more painful by costing £7.50 + vat for four under-flavoured specimens.

If London is a city overloaded with a choice of the different cuisines of the world, all of them over-priced, many of them Europified or Britishofied, then Calcutta is the opposite - the top grub here is what has been the best since at least half-a-century, if not longer. The traditional local street food is among the most interesting in the world; the different Bangla cuisines are amazing, though many subtleties and variations can still only be found in people's homes and not in restaurants; there is a decent smattering of stuff from other parts of India that has evolved here, such as Anglo-Indian, Calcutta-Awadhi, Punjabi/ Mughlai; and a smaller selection of more or less 'authentic' subcontinental food from the Northeast and south India and so on. International food of some quality is available, but only in the five-star fortresses.

In comparison, being in Delhi and not London or Calcutta, has its advantages. Delhi has its own great cuisines, the Mughlai, the Bania vegetarian, the various street foods. Then it has the tributary cuisines from other Indian regions: from Chettinad, Kerala and Andhra to Kashmiri wazwan, from a great variety of northeastern food to Gujarati, Rajasthani and Konkani, and not excluding the centre of Chitto Park where you'll get some of the best Bangla khabar outside Bengal itself. But then, besides this already large variety, Delhi has something else, something which Calcutta desperately needs but is unlikely to get soon. Delhi has middle-priced (that is, considerably lower priced than five-star) restaurants that don't over-emphasize this business of 'authenticity'. For nearly 30 years Delhi has had an abundance of Italian, Thai, French and such places, so the whole obsession with claiming to be being 'real' and 'genuine' has lessened somewhat. What has replaced this in terms of excitement is a bunch of places where the menu displays a combination of skill and knowledge of international approaches to cooking with a stress on local produce, sometimes mixed with selectively picked international imports.

So, yes, briefly touring the penumbra of the elite zone recently, I ate a pretty authentic Mexican dinner at a price that was less than rapacious - the dishes tasted 'authentic', the chillies were not local lal mirch but chipotle, ancho and cascabel, the mole was of proper bean, and so on. What preceded the food, though, were cocktails of tequila and tamarind which worked really well. Similarly, there was another dinner where the menu included words like 'medallions' and 'sous- vide', but ultimately one rediscovers one's basic roots in the most unexpected places.

So, in an eatery attached to a museum, a place that's made a culinary reputation for itself, a place without a liquor licence, in a crowded, buzzing environment - what you might call 'lunch'. The menu, by the standard of today's Delhi prices, displays a very reasonable right hand column but that's not what catches one's eye or palate. The food here is inspired by traditional fare from all over the country, non-fancy, beautifully made, inventively taking off from the different regional traditions. There are mini rava idlis, there is a very nice take on sabudana bhajiyas, but most beautiful of all is a version of our very own Calcutta beetroot 'chop', a patty that's balled, breaded and lightly fried, accompanied by a ' masala cream cheese' dip. It reminds me of all the good and ghastly wedding catering I have encountered in Calcutta and it transcends all of it, but with easy humility, with no pomp or pretension. There is a whole tour of India in between, from Assamese black chicken in tingmo bread to paneer wittily sandwiched between white dhoklas, but at the end you again come face to face with Bengal: there are crêpes involving coconut and notun gur, and then a bhapa doi cheesecake that is truly wonderful. To round off our culinary detour, there is also a dessert I didn't try, where western India clearly meets the northern part of the country, something called "Mahabaleshwar Strawberry Golgappe - crispy semolina puffs stuffed with strawberry and cream".

This is not fancy food. If you look at the prices you would pay far more silly money in Calcutta, eating boring old Park Street restaurant fare. This is not food that depends on manchego cheese or miso sauce for effect - it has nothing to do with Spain or Japan. Where this and one or two other Delhi places have happily stolen from is the street food available all over the country, tweaking it, bending its ear, slapping and caressing it a little, to produce a very clean and original set of tastes. Which brings me back to my original point - the mother-in-law of tradition was also once the shy bride of innovation, authenticity- saas bhi kabhi originality-bahu thi.