Handsome sides of dry-cured bacon hang, crystalline, all along one wall; there are pork pies and black and white puddings; faggots and blocks of lard are piled high and appealing in the long display cabinet below.

The shelves are crammed with pickles and relishes, mustards and accompaniments; the wipe-clean boards offer lists of more exotic game - pigeon, rabbit, venison, snipe and woodcock - alongside the everyday cuts and joints on show.

A well-worn beech chopping block and various saws, cleavers and gigantic knives are to hand.

The tiny subterranean shop is stuffed to the beams.

It's Trev's place. He's worked here in the butcher's since he was 12 - about 40 years. It's a great butcher's. I'm addicted to his chipolatas. He was preparing tempting looking mixed grill packages for one of the pubs when I arrived.

I've had the carcass of one of my lambs delivered direct to Trev from judging in the national championships in Shropshire, where, to my amazement, it won National Reserve Champion.

Usually the lambs come back from the abattoir, deconstructed, in a box the size of an overnight bag. But I wanted to take a carcass whole to the butcher, partly so that I could get the shoulders boned and rolled, and partly because I wanted to watch how it all works.

It would be much more difficult to eat your own lamb if you had only one of them. After lambing, we have a couple of thousand sheep; a mixture of breeds, mainly black-faced, Texels and Belgians.

Fred, the sheep farmer, has been crossbreeding the Belgians and Texels to produce a particularly meaty "Beltex" variety - the ones that are winning prizes.

Our flock comprises half a dozen tups (rams), the remainder being ewes and lambs. The ewes give birth to either one or two young, so the numbers boom at lambing time.

The lambs skip around, looking sweet, munching grass, chasing Fred's Land Rover and falling over. They grow phenomenally quickly - ready for the table in less than a year.

I've been observing the sheep closely. They remind me of shoaling fish sometimes. Their favourite pastime is munching, which they do voraciously. Sometimes they want to come towards you, sometimes they want to run away. You can never tell which it's going to be.

They will often, but not always, follow me as I walk over the fields to the station. It's a nice feeling; a gambolling carnival escort, a huge distended, electrified shadow. I never want to go through the gate when I get there. It can be strange at night walking home when you hear them thundering along behind you and you can't see them.

At the abattoir, the innards are removed along with the head and feet. They leave the kidneys in. Lambs' kidneys are the finishing touch to the perfect English breakfast. People seem to struggle more with eating offal than the flesh cuts, but I'm a convert.

There is so little demand for heart and brain that the abattoir doesn't even give you those bits, or the sweetbreads, the pancreas. I first had sweetbreads in France last year; they're impossibly delicious, tender and tasty, the nicest bit of all. I complain about this to Trev, but he says this is the wrong time of year for sweetbreads.

The carcass has been sliced perpendicular to the spine in the centre of the back, so the fat content can be judged. Trev gets his really big saw and bisects the thing along the length of the spine, giving us two sides.

The saw is frighteningly sharp - the first of several shudderingly sharp tools - but the sawing is still physical work.

He lays the first side flat on the block and nicks the bone at the top of the back - the neck end - and invites me to saw off the first chump chop. It's pretty gruesome, but I'm glad I'm doing it myself.

Trev says that normally you don't get these two cuts, one from each side. They are part of the abattoir's commission. They do look like the meatiest lamb chops I have ever seen. "That's dinner," I say.

He saws off the shoulders and the legs, and with a long knife removes the breast and belly, which is very fatty.

I've never managed to do anything good with the breast. He advises me to cook it overnight at a low temperature. He's not wrong.

I want to keep the racks whole, for roasting, but still there are some terrifying moments with a cleaver. It goes so close to Trev's thumb.

There's a ninja quality to his work; one slip and it's all over. This deftness becomes apparent only when he lets me have a go. He bones and rolls the shoulder in about 90 seconds. It's a work of art. The shoulder looks appetising by this point. Trev reckons shoulder is the best bit, so I let him have the other one.

It's all over very quickly. We've got legs, two shoulders, two racks, some lumps for stewing, breast for slow roasting and a bunch of chump chops.

Chopping up my first lamb stayed vividly on my mind for a few days. The anatomy of a sheep is pretty similar to our own, really. I couldn't scratch my ribs without the image of that immaculate carcass springing to mind. I thought about it involuntarily as I lay in bed at night. But, boy, those chump chops were good.

I was a vegetarian for about 17 years. Now here I am, butchering and eating one of my own lambs.

It was the rooks that put an end to it. They came with the farm. We were just about to get married when we laid eyes on the place.

It suggested irresistible pastoral bliss, the full Country Life package - woods, ponds, barns, stables, river frontage. I even found the village cricket pitch on an old map. It looked like the best possible place to play out a marriage.

Through presenting BBC Radio 4's On Your Farm, I've talked to other people involved with agriculture who didn't grow up on farms, or didn't know much when they started. It seems that the decision to become a farmer is always a huge leap of faith.

Fortunately, there are people who can help when you suddenly find yourself with a farm. They're called land agents. I was lucky to find Paddy. I thought it all looked wonderfully pretty, but Paddy explained that the place was more or less a wreck.

Drainage was poor, ditches were blocked, the fences were shot, the hedges needed re-laying, the woodland was out of control. There were rampant thistles and docks.

It had been a beef farm at one time, I'm told, home to the best shorthorn dairy herd in the country. It had not been a good time for beef farmers, and the place had gradually been run into the ground.

Land must be continuously managed. Leave it, and it becomes more and more difficult to get it back into shape. When he put the farm on the market, the beef farmer sold his cattle and rented the fields to a couple of sheep farmers. A grazing let is about the lowest-risk, least-hassle arrangement for a landowner.

The sheep farmers - no one calls them shepherds any more, and they don't have dogs; they have Range Rovers - bring their own electric fences and stock. The sheep just munch everything and keep it all looking tidy.

In return for this, the tenant grazier pays about $50 an acre per year. It's not much, not quite enough to pay the accountant, but land isn't worth a lot - about $3,000 an acre. In a bank, $3,000 would earn more than twice what a sheep farmer pays, but fields are nicer to look at than bank statements. Some people spend their money on art. I guess I bought some nature.

It seemed best to stick with the arrangement that was already in place with the sheep farmers while we improved the land. As part of this process, Paddy insisted that we do something about the rooks.

There were certainly lots of them, a multitude. It's hard to tell exactly how many as they wheel and soar, spectacular and secret, high above the forest. I didn't mind them around the place.

They are a nuisance, though. Along with magpies, jackdaws, ravens and jays, rooks are members of the corvid family. They're tough and clever.

The collective noun for rooks is a parliament, and a parliament of rooks can be deafening. The sheep farmers claim they will peck out newborn lambs' eyes.

This may well not be true, but they do eat other birds' eggs, and if you "let it be", you end up with just rooks. It seemed that the reasonable thing to do was to reduce numbers, to lend a benign hand to the balance of nature, to cull them. Kill them, that is.

Killing rooks is not nice at all. There are no neat boxes for exterminating them; shotguns are the only thing that work and it's a pretty medieval and messy business, which I don't enjoy.

But I felt I was acting for the greater good. It was a hard decision for a vegetarian to make, and the moment I made that decision was the moment I became a farmer.

Farmers have to be responsible for creating a balance in nature. They've got the whole world in their hands, after all.

We really care about animals in Britain, probably more than anywhere else in the world. Still, most people can't tell the difference between a pigeon and a collared dove. It's easy - collared doves taste much nicer. Just kidding.

It is our interest in animal welfare that is leading to changes in farming methods. We're converting to full organic status. Being organic and green is no longer philanthropy; it's simply good business sense.

Sheep farming is, by its nature, quite ethical. They tend to be freerange as that's the cheapest way to raise them. They just roam over the fields. The land must be well-drained, but it's not like you have to soak the soil with chemicals to make grass grow. Sheep have a pretty organic life.

Gradually, agriculture has become a different kind of economy. We want our food to be as cheap as possible; that's the simple reason farming became more intensive.

Nowadays, farmers tend to concentrate on just one thing. There are far fewer farm workers, and the Cotswolds are peppered with beautiful but redundant farm buildings. It's very hard to make money from farming and, as cheap imports proliferate and supermarkets dominate, it's going to get more difficult.

Beef farming is no longer a viable business. We have to import beef because we don't produce enough of it here. It seems ridiculous: roast beef is our national dish - and we'll only have to rely more and more on cheap and intensively farmed imports.

Our local area has been under cultivation for millennia. There are ancient tumuli going back into the mists of time all over the parish.

We have a couple of fields of ridge and furrow, which indicates farming activity here in the Middle Ages. The oldest part of the farmhouse was probably built in the 18th century, right next to a well.

There are wells all around the barnyard. Our plot was at one time part of a vast feudal estate. In its heyday, probably around the time that the posh-ish Victorian wing was built, as well as the dairy shorthorn herd, there would have been many other things happening.

It would have been a model farm, doing a bit of everything. There would have been chickens for eggs and chickens for the table; ditto geese; pigs for curing and pigs for roasting; sheep for wool and for meat. There was a nuttery (which is now extinct) and an orchard, which still remains.

A few dozen people would have worked here, and there would have been arable crops for the livestock and for market, and cereal crops. There was a bakery - I found the traces of the huge old bread oven - and a dairy that would have produced cheese and butter.

Basically, it would have produced more or less everything you would want to find in an upmarket delicatessen in Islington, that trendy part of North London. With the right kind of farm shop on site, I think the old model farm could work again.

That's where I'd like to take things here, eventually. For now, I just have my sheep, or rather my two sheep farmers, and a cheese that's perpetually nearly ready, but we are getting there, slowly. I was talking to the builders early yesterday morning when a man rolled up in a van. He caught my eye and he returned my gaze, squarely. He was wearing a very cool hat. Somehow, I could tell he was here to do some dirty work.

Moments later, I heard a loud crack and went to investigate. He was pumping up the air pistol again, a dead sheep at his feet.

He took the pistol to another sheep's head. I found I couldn't watch. I closed my eyes at the last moment. Crack.

It was horrible. Fred said there was nothing else for it. They were suffering. I can't think of a more humane or reasonable thing to do, but it still put me off my cornflakes.

I've not been to the abattoir yet. I will, though. Everyone should, if only to buy some chump chops.

This article was first published in The Independent, December 27, 2006.