AH, OBSESSION. Something that we chefs are prone to. We have to be, really. Why else would we go through all the messy prep, the tension of service, the truculent customers, the long hours? Obsession; it can be crippling, physically and financially.

And recently, my culinary obsession got the better of me, and I went a little crazy for a while. I’m glad I had friends at work and the most understanding wife in the world to walk me through it.

Let me explain: sometimes I can be reading a magazine or flipping through the TV channels and I happen upon a dish that piques my interest.

Usually it’s something fairly simple, that I can turn my hand to after a little research and a spot of shopping. This time, however, it was a Mexican dish called Chili Verde that I’d only heard of in passing, way back in the mists of time.

It looked amazing, and the little switch in my head went from ‘oh that looks nice’ to ‘you must make this immediately’. And so I emailed my veg man, the wonderful John Lawton at Covent Garden in Lockwood, and asked about tomatillos. This was back in February, I believe. Hard to find, and out of season, I was told. I was undeterred.

The obsession had gripped me. So began a rally of phone calls between the café and the market that has lasted until just the other week, when John called and told me that not only were tomatillos in season, he could get me a box. And, long pause, was I sitting comfortably? Reader, the box, holding about 4kg of sweet green tomatillos, cost £50.

That is not cheap. Not by any stretch of the imagination. But it was too late; the obsession was now in charge. Quickly deciding against two boxes (I’d wanted to play about with them for other recipes too) I said yes, and a box duly arrived, all the way from California. Normally, my guilt about food airmiles would have caused anxious thoughts, but the gremlin in my mind just told me to forget it and get cracking.

I called in at the farm shop and picked up a huge bag of pork, and, a few other ingredients purchased, I was finally ready. I remember clearly that I actually said to myself, out loud, “this, old son, had better be worth it!” And it was. Thank the heavens it was.

The chili verde is an alternative version of the classic Mexican chili, based around a deep green sauce made with the well-travelled tomatillos, plus chili, onion, garlic, spices and herbs. It is a relatively mild chili, which allows all the flavours to shine, rather than cowering beneath the heat.

It can be made with chicken or seafood, but the pork works its meaty magic really well with the spices. The tomatillo, which looks like a large green physalis (Cape gooseberry) tastes a bit like a combination of said fruit and an unripe tomato, half sweet, half savoury and very fragrant.

When roasted gently, the sharpness dissipates a little, and after a couple of hours’ cooking with the rest of the ingredients, it gives a wonderful, fresh-tasting clean tomato-y flavour.

I must say, though, having tried the tomatillos both raw and cooked, I reckon this recipe would work just as well with the humble green tomato, something of which we have no shortage in the UK at the right time of year, and which doesn't come all the way from the USA at vast expense and bother.

So, thanks to John, the good folks at Covent Garden, and my temporary insanity, here it is: the chili verde recipe. I won’t suggest you all try it at once – we could crash the economy.

Just tuck it away somewhere and wait for the green tomatoes. I wouldn’t want any of you to go quite as potty as I did. Aprons on!

Ingredients

2kg locally-reared pork shoulder, trimmed and cut into 2in. cubes.

675g fresh tomatillos (or green tomatoes)

8 garlic cloves, whole, unpeeled

2 small jalapeño chilis, chopped (or 1 scotch bonnet)

2 large green Anaheim-style chilis, chopped (or 4 green peppers)

2 large onions, finely chopped

4 garlic cloves, minced

1 large bunch coriander, washed and lightly chopped

2 tbsp fresh oregano

4-6 avocado leaves (optional)

About 600ml strong chicken or pork stock

1 tsp ground cloves

Maldon salt

Freshly ground black pepper

Olive oil

Method:

Heat the oven to 230ºC / Gas 8. Remove the papery husks and stalks from the tomatillos, rinse the fruit well and allow to dry.

Cut them in half and place them, cut side down, along with the unpeeled garlic cloves, on a well-oiled baking tray.

Roast in a hot oven for about 15 minutes, until they start to colour. Cool slightly.

Gently push the roast garlic flesh out of the skins into the tomatillos, and blend the whole lot to a smooth sauce.

Add the chopped jalapeños, the large green chilis and the chopped coriander, and reserve this bright green sauce until later.

Season the pork cubes generously with salt and pepper. In a wide frying pan, brown the pork in batches in a little hot oil.

Add the ground cloves to the final batch when you’re just about finished, and tip into a large casserole or stock pan. Add the tomatillo sauce.

Fry the onions and fresh garlic gently in the pork fat until soft and golden, then add to the pork in the stock pan. Add enough stock to just cover the meat.

Add the avocado leaves, if you have them. Bring the pan to a boil and then reduce to a very gentle simmer.

Cook for 2-3 hours, uncovered, until the pork is fork tender.

Add the chopped oregano and check the final seasoning.

Serve with some fluffy long-grain rice or fresh soft tortillas.