It's no great surprise that Bird, Jim Collins' wife, is adept at hiding vegetables in the lunch she is preparing for her three young boys and their two cousins. After all, their 1,500-acre organic Essex farm, Ashlyns, near Epping, has just begun supplying 22 local school canteens with a service that includes comprehensive healthy meal plans, organic or local produce to make the meals and full training for all their kitchen staff in the farm's on-site training kitchen.

'Mummy, mummy, it's chicken nuggets and chips!' shrieks a very happy Harry, as he sits down in the kitchen of their 16th-century farmhouse. 'If that's what you want it to be, then yes it is,' replies Bird, before explaining that today's lunch is actually organic pork, twice dipped in beaten egg, breadcrumbs and ground sunflower seeds ('They don't even know the seeds are there, it's just an easy way to get goodness into them'), then baked in the Aga. The 'chips' are actually Nicola potato wedges (grown on the farm) that have also been baked with a dusting of smoked paprika. Then there's special orange and green pasta, which is really spaghetti mixed with thinly pared strips of courgette and carrot. 'Of course,' sighs Bird, 'I'm going to get found out because I've added broccoli, and Sophie [Bird's niece, who is four] doesn't like eating green things.' Everyone also gets a little piece of baked fish and a fresh bread roll. For those who can manage pudding, and for small people there are a surprising number of takers, there is a special treat of homemade chocolate brownies.

'I cook with organic ingredients from the farm shop, and I do a lot with the kids, especially Luke [four], who really loves mixing,' says Bird, who does much of the buying and sourcing for the three Ashlyns farm shops that stock everything from treats like organic shitake mushroom pâté to basics like organic wholemeal gnocchi and organic flour.

'I used to be a salmon-smoker, smoking local salmon, so food has always been a big thing for me. In fact, I come from the next village, and I grew up knowing Jim, so I haven't exactly gone far.' Nonetheless, Bird is a very long way from the archetypal farmer's wife, with silver toe rings on her bare feet and a small tattoo on the inside of her forearm.

This isn't the first time the Collins' kids have been photographed, as Lucy, who is seven, is keen to relate between mouthfuls. 'We've been famous before. We were there when Jamie opened the kitchen and when he cut the ribbon, and the ribbon was made from vegetables.'

She's talking, of course, about Jamie Oliver, who came to Ashlyns last October to offi cially open the Feeding our Future dinner lady-training kitchen situated a couple of miles away on another part of the farm. Oliver's link with the project came via Jeanette Orrey, one-time dinner-lady extraordinaire (and Observer Food Monthly award winner in 2004), now school-meals policy adviser for the Soil Association.

After Essex County Council handed back control of school meals to local schools in March 2004, the Ashlyns team realised this was an ideal time to create a service combining the delivery of organic and local produce to school kitchens, as well as high-quality training to kitchen staff, all within the schools' budget. Orrey was instrumental in setting up the kitchen at Ashlyns - a personal dream of hers that took two-and-a-half years to achieve with the help of a DEFRA rural-enterprise scheme matchfunding grant. Due to her involvement, the farm is now a demonstration farm for the Soil Association, and forms part of their campaign to improve school food via their Food for Life project. Ashlyns' aim is to encourage school dinner ladies to learn more about the food they are providing for their pupils

'Jamie Oliver has done a great deal for awareness and he's moved things forward very fast in that head teachers are now much more interested,' says Jim, later on that day in the training kitchen. 'But,' adds Gary Stokes, Ashlyns' highly energetic project manager, 'we've been working on this a lot longer. Because people are more aware of what their kids are being fed, the uptake of school meals has dropped, which in the end is no better. The exciting thing about our project is that we can encourage them to eat school meals again.'

'We wanted to replicate school premises,' says Jeanette, running her hands over the stainless-steel surfaces in the training kitchen. 'There's nothing here that school cooks don't have, it's just that ours are shinier.'

'Everything except the Rational cookers,' points out Jim, 'they're much more hi-tech than the ones most schools have. They can bake, grill, steam, and roast.'

'You can do 300 meals in one of these, and because you don't have to"hot-hold" food, if you do something like broccoli, the last kid gets vegetables that are as fresh and hot as the first kid in line did. They evenclean themselves,' says Jeanette with not a little pride, demonstrating that you can specify how brown you want your grilled chicken or gratin potatoes, using the little digital display to adjust the settings.

'They are approaching idiotproof,' grins Jim, 'but I'm fairly sure I could still mess it up. Bird is such a good cook, that I honestly don't think I remember how to do it.' ('I think Jim made pancakes once in about 1998,' Bird had laughed earlier when asked who didmost of the cooking at home.)

About 300 dinner ladies have come through the training programme since it launched late last year. 'We have a maximum of 15 ladies per course, with three training chefs, and three work stations. We like to teach everyone who works in each kitchen, as we've had situations where a kitchen assistant who barely speaks English has proved to be an incredibly accomplished cook, but has never had the chance to show anyone. We've even had head teachers attend, which is completely brilliant, because they always say, "I had no idea how much there is to do in a school kitchen",' says Jeanette.

On the first day, the cooks are often very shy, but they usually relax by day two, when they prepare lunch for each other and whoever else might be around. 'You get a great feelgood factor when you bring people in for lunch,' says Jim. 'There's nothing better than bringing in the bank manager and giving them food you'd pay a lot for elsewhere.' Jeanette is flourishing a typical menu from the course, full of exciting food that children wouldn't find too challenging: lambburgers with yogurt, salmon fish fingers, savoy cabbage and bubble and squeak.

'You do realise how endemic the problems in school kitchens can be,though,' says Jeanette, 'as there is occasionally someone who, even at the end of the course, won't eat the food they've just cooked - they're still suspicious of vegetables.'

The training kitchen has also opened its doors to care-home staff, and most recently to 16-year-olds leaving care. 'A lot of these kids will go on the dole for a bit, and so we try and given them the skills to cookhealthily and straightforwardly on a very low income.

At the end of their three-day course they do a sort of dinner party for the staff and some guests, often people from social services, and they always work incredibly hard for it all to be perfect. Often people really shine: one of them is now in Jamie's kitchen,' says Gary Stokes. 'I went off to an awards party in London after one of their evening meals,' recalls Jim, 'and the food was a lot better here.'

'There are a few drop-in centres for these kids, which have kitchens,' says Gary, 'and we've heard that some of them have started cooking in them for their mates.'

It's taken them two-and-a-half years to get to the point of being able to supply their local schools, and, although people attend from Wales, Lancashire and the Midlands, now they'd love to roll out the model in full to other counties. Gary explains, 'We give schools a package which includes everything but the dinner ladies - health and safety, hazard analysis and meal plans, which we reassess after they've done the whole plan through twice. It's very brave of the schools really, because it means giving up using catering contractors.'

It's been hard to get the ethos across, but they've been lucky enough to get the backing of a local producers group. 'There are 40 farmers working with us very enthusiastically,' says Jim, 'and we're offering a big alternative market to selling to supermarkets.' Because of the co-operative, they can usually source everything for the schools organically, but if not, at the very least it's all locally produced.

Back in the farmhouse kitchen, the Collins tribe, suitably refuelled, stampedes out into the garden dragging au pairs in their wake, and the assembled grown-ups somehow make do with Bird's delicious pasties, filled with smoked haddock, leek, crème fraîche and chives, along with a few more of the Nicola wedges. Bird's 22-year-old parrot, a blue-fronted Amazon who hates everyone except Bird, is another fan of the wedges, and eats one standing on one leg on the dresser. Even the labrador is tucking into organic broccoli under the kitchen table.

Spicy lamb burgers with yogurt dip

These were devised by Simon Owens, who works with Jeanette Orrey in the training kitchen.

Makes 16 burgers

For the burgers

1⁄2 bunch fresh coriander, washed and chopped

175g onions, finely chopped

1 small red chilli, deseeded and chopped

1 tbs olive oil

1kg minced lamb

1 tsp ground cumin

1 tsp ground turmeric

1 tsp ground coriander

1 egg, beaten

For the dip

1 small cucumber

300ml natural bio-live yogurt

2 tbs finely chopped fresh mint

1⁄2 tsp ground cumin

freshly ground black pepper

To make the yogurt dip, peel the cucumber and grate it into a bowl, then mix in the yogurt, mint, cumin and some pepper. Chill before serving.

To make the burgers, cook the onion and the chilli in a frying pan until soft and golden. Leave to cool a little. Combine all the burger ingredients in a large bowl and stir thoroughly. Divide the mixture into small burgers. Place on a baking sheet and grill for 3-4 minutes on either side, or for the same length of time on a barbecue. Serve in a warm half pitta or mini burger bun with a salad of chopped carrot, tomato and cucumber. Add a squeeze of lemon to the burgers once they are cooked.

Taken from Second Helpings from the Dinner Lady by Jeanette Orrey (Bantam Press, £18.99)

· Ashlyns' farm shop and mail-order service can be contacted on 01992 525146; www.ashlyns.co.uk. The training kitchen is on 01277 890821; www.ashlynsorganics.co.uk. Second Helpings from the Dinner Lady by Jeanette Orrey (Bantam, £18.99)