We chefs are never happier than when we can go back to basics. We can get so immersed in the showmanship of running a busy restaurant that it is easy to forget what cooking is all about – transforming simple, raw ingredients into a delicious, nourishing meal. And, no offence to Hugh Fearnley-Whittingstall, there’s nothing more basic than a trip to River Cottage.

With Hugh, what you see is what you get, and in the case of his “Lamb and Mutton in a Day” workshop, that means Hugh, his butcher Ray, a dead sheep and 25 enthusiasts gathered together in a chilly barn in deepest Dorset.

Hugh is a real chef’s chef – what he doesn’t know about husbandry and butchery isn’t worth knowing – and his approach is one very much after my own heart. In today’s finicky world of cooking, it’s great to meet someone who celebrates produce in its entirety – blood, guts and all.

In short, Hugh’s philosophy is that meat should be something to be celebrated and savoured, and the best way to do that is to treat the animals with respect. That means, of course, looking after it properly when it’s alive, but also doing it justice in the kitchen, making the most of every last scrap. If the animal has died for us, the least we can do is make the absolute most of it.

“Food animals are killed and cut up far from human eyes. By the time the meat reaches the consumer, its animal origins have all but been obliterated,” he complains. We start to see meat as prepared, dinner-party cuts, like racks of lamb or fillets of beef, instead of considering the entire animal.

No chance of that here. As Hugh speaks, a whole sheep carcass is hanging behind him, and over the course of the day it is gradually dismembered and cooked until he is left, literally, with the bare bones. And even they will end up in the stockpot.

After a quick look at some of his sheep out in the fields, a Jacob and Dorset Down cross – “my favourite eating sheep, and they make very good sheepskin rugs”, says Hugh, right to their faces – it’s down to business. “There’s very little you can’t use, although the intestines do need a lot of prepping. You have to wash them very carefully. About the only thing you don’t get back from the abattoir is the spleen. I don’t know why. We get pigs’ ones but not sheep’s.”

First off is paprikash, like a goulash, using hearts and tongues, “a great house special on Valentine’s night”, Hugh jokes. In go sweated onions, the meat, tomatoes and water, plus plenty of paprika – sweet and smoked. Smoked paprika is such a lovely spice, and great for colouring things without giving too much intensity of heat.

Like a lot of the less popular cuts, this needs long, slow cooking to get the best out of it. Once it’s bubbling away happily, Hugh puts it to one side on the hob. “Now I’ll deal with the kidneys for your elevenses,” he says. “These always make a convert of kidney haters. Because they are so fresh, they are sweet and creamy.” Sure enough, with plenty of port and sherry, mustard and cayenne (“to blow you away”) and a trickle of cream, they have none of that uric tang you sometimes get with kidneys. Absolutely delicious.

Next up is a modern take on haggis. I grew up around every offcut – skirt, liver, heart, tripe – so from an early stage I’ve never turned my nose up at it. Every time I went to see my gran in Port Glasgow, the first thing I could smell was tripe, which my grandad used to eat twice a day. Hugh is using the aorta, heart, lungs and liver, collectively known as the pluck. He holds these innards up like some anatomical model, like that weird German bloke doing those televised autopsies. Hugh being Hugh, he explains that he likes to keep in more blood and use less cereal in his haggis, a bit more like a black pudding.

And so the day continues. Sliced liver on sourdough by way of a canapé leads to lunch of breast of mutton stuffed with apricots, thyme, garlic and shallots. Afterwards, there is merguez made with diced shoulder, citrus-braised lamb shanks, shish kebabs from chump end and Lancashire hotpot with best end, neck and chops. And Hugh’s still got four legs left over for a traditional roast.

It’s an amazing day, and one I’ll get the brigade from Claridge’s down to witness soon. You can’t come away without a renewed respect for mutton, British meat in general – and for Hugh himself. But thankfully this time he stopped short of placenta.

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