Then suddenly, on a sight-seeing visit to the historic papal city of Avignon, they found their Holy Grail. We'd been directed to Avignon's one and only Vietnamese restaurant (not one of the 25 restaurants listed in the city's Michelin Guide).
So much did they enjoy it, we had to order seconds. There were spicy soups with rice noodles and shredded vegetables, sharpened with lemongrass and tingling with chilli.
There were spring rolls with minced pork and crab, and crunchy bean spouts wrapped in fine rice paper. And pieces of marinated chicken, prettily wrapped in lettuce and smothered with mint, spring onions and crispy, crushed, roasted peanuts. These were served with sweet ginger, galangal and soy dipping sauces, and the fish sauce called nuoc-mam. The visual appeal was enhanced by the promising smells. And the total sensual experience was perfected by keen, very fresh tastes.
Paris has a good share of Vietnamese restaurants. A dozen do make it into that city's Michelin Guide - quite a tribute to their quality, considering MG's francophile prejudices. Their presence is due to a French colonial influence in that part of the world dating from the 16th century.
But Vietnamese food is hardly known in the UK (there's Soho and that's about it). So, short of a trip to Vietnam (which entertains only about half a million tourists a year) or a sortie to Avignon or Paris, the best way to get an insight into this delicious food is by means of a new book, Street Cafe: Vietnam, the first to be published in the UK devoted to Vietnamese cooking (see book offer overleaf).
Its British author, Annabel Jackson, says this is a cuisine whose time has come. "It's the most contemporary of foods, one of the healthiest and the tastiest. It's low in meat and high in fish and raw vegetables. It combines the spicy appeal of the foods of China and Japan, but it's very different."
If Vietnamese food is not on everyone's hit list, there is good reason. The Vietnam War (which is known in Vietnam as the American War) eclipsed all cultural or social aspiration, driving the country into deep hardship and poverty from which it has only just started to recover. Ten years ago, the north of the country was still devastated.
Annabel Jackson is a food writer based in Hong Kong. She first travelled to Vietnam 10 years ago and soon became a regular visitor. Although she rather stumbled on Vietnam by accident, she was an instant convert. "I know this sounds very wet and New Age, but Vietnam appealed to my soul. At once I felt I must have been Vietnamese in another life," she says with humour.
The food scene, she says, has only re-emerged in the last five years, but its roots go deep. Influenced by the French (you even encounter people in Breton berets bearing fresh-baked baguettes home), its best cooking exhibits great sophistication.
Historically, the Vietnamese are a mixture of Chinese and Malay. The use of chopsticks and love of noodles reflects the Chinese side, but the Malaysian influence is marked by their fondness for Indian curry spices, especially in the south. Their passion for fresh herbs, unusual in eastern cuisine, Annabel credits to the influence of the West.
Of all the Eastern cuisines, says Annabel, it is the only one which offers a breakfast experience she enjoys. Japanese breakfast dishes of rice and salty pickle are too confrontational. Chinese congee, glutinous rice, is less than appetising.
But a Vietnamese breakfast bowl of soup with sloppy noodles is a revelation, both delicious and refreshing. This soup, known as pho, is offered in restaurants, bars and street stalls everywhere.
Simmering on a hob is a great pan of meat stock, seasoned with star anise and roast ginger. Each customer gets a bowl with shavings of beef, spring onion, mint and coriander, and the boiling stock is poured on top. At once, the aromas of the herbs are released. You add whatever extra flavours you want; soy sauce, hot red chilli sauce, or nuoc-mam.
Nuoc-mam is the universal, highly seasoned fish sauce. It is a clear brown liquid which is made from draining the fermented juices from small, salted fish similar to anchovies. In large quantities it is unbearably pungent, but just a few drops add a wonderful savoury nuance.
Vietnam has many unique dishes; a thin pancake steamed on a muslin cloth is one such. The batter, made from finely-ground rice, is scraped off the cloth when cooked, to be wrapped around minced pork and dried black mushrooms, served with crisp-fried shallots and a sauce of nuoc- mam, chilli, vinegar and sugar. It's called bahn cuon.
The most popular vegetables include long, thin, purple Asian aubergines, as well as numerous sorts of greenery. Cucumbers, bean sprouts and under- ripe bananas are also much used. Shallots, spring onions and dried mushrooms are very important seasonings. And the list of herbs is long: many kinds of mint and basil, coriander and dill are used; and flavourings such as star anise, cinnamon, ginger, limes, tamarind pulp, lemongrass and of course, very hot red and green chillies.
The important base ingredient is the noodle. Egg noodles made from wheat flour and egg are similar to Chinese noodles; rice noodles, almost transparent, are made from white rice flour and come in all shapes and sizes, bought fresh in the markets each morning. And the very fine bean-thread vermicelli, made from mung bean flour .
So here's a start-up kit for the healthiest new cuisine on the block; a taster of Vietnamese dishes, including some of Annabel Jackson's favourites and adapted for the British kitchen. The ingredients can be bought in Asian stores everywhere.
HOT AND SOUR FISH SOUP
The Vietnamese use a whole fish in the stock for the soup, particularly the head which has such sweet flesh, but use fillets if you prefer. Fish such as perch, pike, sea bass and grouper are suitable.
Serves 4-6 as a starter
280g/10oz whole fish or fish fillets
1 teaspoon sea salt
115g/4oz okra, sliced diagonally
225g/8oz tomatoes, each cut into eight wedges
1 fresh red chilli, thinly sliced
1 dessertspoon tamarind pulp
1 tablespoon nuoc-mam
85g/3oz peeled fresh pineapple, cut into small pieces
1 tablespoon finely chopped fresh rau om (if available)
If using a whole fish, cut into three. Place the fish in 850ml (11/2 pints) of water, add the salt and simmer for about 10 minutes, or until the fish is soft. Remove the fish with a slotted spoon. Add the okra, tomatoes, beansprouts and chilli to the stock. Simmer for 10 minutes, or till the vegetables are tender.
Meanwhile, soften the tamarind pulp in a few tablespoons of the fish stock in a small pan over low heat. Remove the seeds, then add the resulting paste to the soup. Add the nuoc-mam and the fish and simmer for a further five minutes. Add the pineapple and rau om, if using, and simmer for another five minutes, then season and serve.
PRAWN AND PORK ROLLS
One of the most delightful and popular dishes in Vietnamese cuisine, these rolls are deliciously light and healthy. Left-over roast pork can be used.
Makes 8 rolls
8 dried rice papers (20cm/8in diameter)
55g/2oz beansprouts, ends removed
a selection of fresh basil, mint and coriander leaves
115g/4oz rice vermicelli, boiled quickly in water
115g/4oz boneless pork, boiled and thinly sliced
16 medium-sized prawns, steamed and peeled
For the nuoc-cham dipping sauce:
1 tablespoon nuoc-mam
3 tablespoons lime juice
1 garlic clove, finely chopped
1 fresh red chilli, finely chopped
1/2 teaspoon caster sugar
Soften the rice papers by lightly brushing each one with warm water. After 20 seconds, fold in about 2.5cm (1in) on the two opposite sides and the top.
For each roll, place a lettuce leaf on a paper and pile on a few beansprouts, herb leaves and vermicelli. Add some pork and two prawns, and roll up.
Combine all the ingredients for the dipping sauce with two tablespoons of water. Serve the rolls immediately, with nuoc-cham for dipping.
SOUTHERN VIETNAMESE CHICKEN CURRY
Vietnamese chicken curry is neither Thai, Indian nor Chinese in style. This is a rather heady, aromatic dish. Throw a handful of freshly torn Thai basil on top and some freshly ground black pepper to bring out the fragrance. Serve with rice vermicelli rather than rice for added interest.
2 medium-sized potatoes, cut into chunks
vegetable oil for frying
8 shallots, finely chopped
4 stalks fresh lemongrass, finely chopped
2 garlic cloves, finely chopped
2 fresh red chillies, finely chopped
2 tablespoons mild Indian curry powder
450g/1lb skinless, boneless chicken breast in bite-sized pieces
1 teaspoon sea salt
300ml/1/2 pint coconut milk
600ml/1 pint chicken stock
fresh Thai basil leaves (optional)
Shallow-fry the potato pieces in hot oil until lightly browned. Drain on kitchen paper and set aside.
Heat a little oil in a pan and saute the shallots with the lemongrass, garlic and chillies until soft. Add the curry powder and stir for two minutes. Add the chicken and cook, stirring until it is opaque.
Add the potatoes, salt, coconut mild and chicken stock. Bring to the boil, then cover and simmer gently for about 30 minutes. Garnish and serve.
Stuffing small squid is fiddly, but worth the effort. If your squid have tentacles attached, finely chop these and add to the filling. This is quite a dry dish so is best served with other, sauced dishes.
450g/1lb young squid, cleaned and patted dry
vegatable oil for frying
For the filling:
3 dried Chinese mushrooms, soaked in warm water for 30 minutes, then finely chopped
25g/1oz bean-thread vermicelli, broken into pieces and soaked in warm water for 30 minutes
175g/6oz boneless pork, minced
2 shallots, finely chopped
1 garlic clove, finely chopped
1 dessertspoon nuoc-mam
pinch each of caster sugar, sea salt and freshly ground black pepper
Combine the filling ingredients, mixing well. Stuff each squid with the filling, packing it in firmly. Secure the opening with a wooden cocktail stick or sew up with a trussing needle and fine cotton.
Fry in a little hot oil over a moderate heat for about 15 minutes or until nicely browned on all sides. After the first few minutes of cooking, pierce the squid with a sharp pointed knife to release any water.
Leave the stuffed squid to cool for a few minutes, then cut each one across into 1cm (1/2in) slices and serve immediately.
CHICKEN AND LEMON LEAF SALAD
Vietnamese salads must be served extremely fresh or they lose their texture and become soggy. The Vietnamese use rau ram in this classic dish; mint is the best alternative. Lemon leaf adds texture as much as flavour but can be omitted.
Serves 4-6 as a side-dish
225g/8oz boneless chicken, shredded
1/2 onion, thinly sliced
1/2 cucumber, seeded and thinly sliced
6 tablespoons finely chopped fresh mint
4 fresh lemon leaves (if available), shredded
For the dressing:
juice of 3 limes
1/2 teaspoon sea salt
1 teaspoon caster sugar
Combine the ingredients for the dressing, stirring well, and set aside. Mix together the chicken, cucumber, onion, beansprouts, fresh mint and lemon leaves. Toss with the dressing, serve immediately.
GRILLED AUBERGINES WITH SOY SAUCE
The Vietnamese often top grilled aubergine with crab meat or minced beef. This is almost a vegetarian version, given a sprinkling of nuoc-mam.
Serves 2-4 as a side-dish
2 Asian aubergines
4 spring onions, finely chopped
2 tablespoons vegetable oil
2 dessertspoons soy sauce
1/2 teaspoon nuoc-mam
Prick the aubergines in several places with a fork, then grill (preferably over a charcoal fire) for about 20 minutes, or until the flesh is soft but before the skin burns. When cool enough to handle, peel the aubergines and cut them in half lengthways.
Put the spring onions into a bowl. Heat the oil in a pan until very hot, then pour over the onions. Drain immediately. Sprinkle the onions over the aubergine, then gently pour the soy sauce and nuoc-mam on top. Serve.
This delicious little snack is frequently prepared along village streets, where women set up stalls in front of their houses. In Vietnam, cooks use the small, broad Thai cooking bananas.
55g/2oz plain flour
25g/1oz caster sugar
1 egg, beaten
60ml/2fl oz milk
675g/1lb 8oz bananas
vegetable oil for frying
Mix together the flour, sugar, egg and milk to make a smooth batter- like paste. Leave to rest for one hour. Slice each banana in half lengthways, then across into chunks about 7.5cm (3in) long. Dip the banana pieces into the batter and shallow fry in hot oil for a few minutes, or until golden brown all over. Drain on a wire tray and serve warm. !
Street Cafe: Vietnam by Annabel Jackson is available to readers of the Independent on Sunday at the special price of pounds 11 (including postage and packaging) instead of the RRP of pounds 12.99. To order your copy of Street Cafe: Vietnam by phone please call Conran Octopus on 01933 443 863 with your credit card details, or to order by post send a cheque, made payable to Octopus Publishing Group, to Conran Octopus Books Direct, 27 Sanders Road, Wellingborough, Nothants NN8 4NL. When ordering please quote reference H407.