Local eats: Kasturi, EC3

A great meal, no matter the cost, is usually pretty straightforward - you sit, eat, drink, laugh, say 'wow' plenty, before paying the bill without feeling bitchy about leaving a decent tip. You trundle home feeling splendid. Sometimes a meal is great for other reasons - good food not only educates your senses but provides a geography and anthropology lesson, too.

Did you know, for example, that the Indians use hot spices in their food to regulate their body temperature? So the hottest regions have the most chilli in their cuisine. It's an obvious sort of a fact, but one I would not have ingested had I not eaten the odd curry sober and with a curious mind.

My brain got a good workout over dinner at Kasturi, an Indian restaurant serving the cuisine of India's North-West Frontier. We got talking to the owner, Nur Monie, who describes the food as Pakhtoon. 'As in Pashtun?' I say. 'Aren't they from Afghanistan and Pakistan?' 'Yes,' he says, 'But...' Cue long talk about borders drawn between Afghanistan, Pakistan and India in 1893 by the British. And what a not terribly comfortable place the old North-West Frontier would be to eat a curry these days. Cue long talk about the Moguls ruling India and bringing Pashtun food down into the Indian subcontinent over 600 years ago. Followed by long talk about the evolution of the Pashtun's mild and simple mountain food into the exquisitely and delicately spiced food we have before us. I wish I had the space to tell you all the interesting things we discovered through eating a splendid meal.

My stepmother was tired, and she said that the sparkling smell of the spices as we walked in the door woke her up - this from a woman who needs three espressos to get her up in the morning. I am not a curry buff, I don't have a taste for ghee, nor do I have memories of beery school exeats to the Raj in Buckingham. But the menu here has little I have seen before on it and the food of this region uses vegetable oil, or simply the juices of the meat, to cook with. There are few Pakhtoon restaurants in town (I found one other), and for aficionados of regional Indian cuisine it's a trump card.

There is a patronising 'all time favourite dishes' section on the menu with your rogon josh, your chicken tikka massala, your dansak. Nur Monie said it was for 'you know', meaning the sort of people who go to curry houses with their brains closed.

A large chunk of my family and I ate so many exciting dishes, I can only offer edited highlights. A starter of kabab-ke-karishma, a selection of meat kebabs cooked in the tandoor oven, had mindblowing succulence, juiciness and the most intricate spicing.

My brother once had a biryani in Southampton which consisted of rice, banana and a fried egg. To compare this to the biryani, mashqetanjan, set before my sister George would be like comparing a 19thcentury cognac with a bottle of Sarson's. It was so full of tastes, textures and sensual warmth.

Koh-e-avadh, knuckles of lamb cooked in its own cardamon-tinged juices, was ragged and melting. The peshwari nan came scattered with sesame seeds and honey. A side order of dal-dera ismail khan, black lentils with herbs simmered with cream over a slow charcoal fire, was a thrill. From so little, so much.

Am I being a bit OTT? OK then, bad stuff? The Pinot Gris we ordered was a little warmer than is right and the atmosphere a little lacking - there were few people in the restaurant on a Friday night.

Kasturi is having a kebab and biryani festival until Sun 15 Jun. If you have yet to get in on the citywide rise and rise of that once culinary outcast, the kebab, then get down there. Sister George said of the murgh dharanpur, a kebab of chicken and cheese, 'That's what KFC tastes like in its heaven branch. This is Jesus food.' I never knew she was religious.