Rick Stein And The Japanese Ambassador (BBC2): 'This is the bees knees," exclaimed chef Rick Stein as he studied Japanese cooking. Goodness, I thought, is there no part of any creature that the Japanese won't eat. Besides, I never knew bees had knees.

Stein was expressing his delight at the Japanese chefs and their dishes on his first trip to their country.

The Japanese Ambassador in London had seen Stein on TV preparing sushi for holidaymakers in Cornwall and invited him to cook a banquet for him and his guests at his London residence.

This was a real challenge for Stein who'd never been to Japan. The enormity of what he'd taken on cooking Japanese food suddenly hit him. "A fine kettle of fish I've got myself into this time," he said. An apt turn of phrase as the Japanese love eating fish.

He visited the Japanese fish market that's the biggest in the world, selling $20m of fish every day. It's a figure that doesn't seem so unlikely on hearing that a tuna costs £5,000, rising to £20-25,000 at Christmas, with the most expensive fetching an amazing £50,000.

The first half of the programme, as he discovered Japanese food and cooking, was a real eye-opener. Not just the price of fish but seeing a vast warehouse of frozen whole tuna waiting to be sliced up - very much like the scene with the pods in Alien, suggested Stein.

The chefs preparing sushi presented plates of carefully-arranged, colour-coordinated food that could pass as works of art. Even the domes of ice covering the dishes were beautiful.

He learnt that the Japanese like fresh food linked to seasonal changes.

Of course his research involved much eating out, from a local diner serving just one dish (locally caught clams and rice) to a nine-course banquet given in his honour by an ex-Prime Minister of Japan.

After a week of learning, it was back to London to cook a banquet and more familiar TV chef territory - the kitchen, where he had help from two Japanese cooks. He was confident that if your ingredients are fresh, everything else falls into place.

They did indeed produce food that looked good enough to eat, and it does you good as well.

A fish diet is a healthy one that allows you to live longer. Bald men might be rushing to the sushi bar too after it was revealed that kelp, one of the vital ingredients of many Japanese dishes, makes your hair grow.

The ambassador and his guests, I must report, were very pleased with Stein's banquet. The BBC must have been too as they repeated the programme last night just days after it first aired.