If you take a clear, well made, lightly gelatinous fish stock, season it with salt and sweet white vinegar and infuse it with lovage, mint and celery leaves, the result is a clean soup – a bone broth, if you must – which sits happily in the sometimes awkward period between summer salads and the dense potages of winter, although it might seem a little austere. Add some diced golden and orange tomatoes and gently warm through until the jelly round the seeds seeps out into the pan, then spoon the lot into a plain white bowl, where it will glow with brisk, late summer health. You might have started the bowl with some flakes of salt-baked gurnard, poached, shredded skate wing, or a lightly cured mackerel fillet, barely cooked through in a little spare broth; you might finish it with a fistful of chopped dill, fennel tops and parsley or a spoonful of a pungent, quivering aioli.
This is a way of cooking, precise and simple, that can only proceed from abundance, and as such is incredibly irritating to read about. No-one wants to hear about your well-stocked larder, your fridge full of home-made condiments and seasonings – I’m sorry for bringing it up. In my defence, ours is professionally so, with space to spare in cupboard, freezer, and dishwasher, and the time, inclination and imperative to do the kind of housekeeping, the straining, simmering, bottling, pressing, potting and drying which formed the backbone of our imaginary peasant cuisines; outside of work, it’s a fantasy, but one that it’s nice to inhabit for a while. I don’t think I’ve ever made fish stock at home. Meat broths can be thrown together out of ham bones or roast chicken carcasses, a few scraps of veg, simmered for hours with little attention, but fish needs a bit more care.
If you wanted to follow the non-recipe above, taking the mackerel option, then you’d need to start with another fish entirely. The bones of oily fish do not make a good stock. You want white fish carcasses (flatfish are good), which you’d need to ask your fishmonger for, if you have one and he likes you, or save from a previous meal of, say, fat bream you’ve filleted yourself – which brings us back into the realms of fantasy. I don’t think I’ve ever filleted bream at home either – I roast them whole, and the roast bones do not make a good stock. Cheap white fish fillets will do. Put them, or the bones, in a pan with onion, fennel, celery, peppercorns, bay – you know, all the standard stock accoutrements you have lying around your well-stocked pantry. Cover with water and bring to a bare simmer, which is where it should stay for about half an hour. “There was silence throughout heaven for about half an hour” – that’s when they were making fish stock, carefully watching the bubbles to ensure it never broke out into anything as frantic as a putter. I assume so, anyway.
When it’s ready, you can lift out all the bits with a sieve and pour the clear liquid into a bowl or tub containing lovage, if you can find it, mint and celery, leaving behind any fishy sediment. Lovage is an excellent herb, something like an intensely astringent celery, which I have never seen for sale anywhere, although it grows in this country fierce and strong. You can leave all that to infuse like some unpleasant, medicinal tea, before straining and, if you like, freezing the result. If you do the latter, then take the opportunity to clarify it upon defrosting – it’s an extremely easy process, but one I can’t be bothered to explain here; just writing all that about stock has exhausted me. Google, google, google. Time to cure the mackerel, if you’re still with me. You need ridiculously fresh fish for this. Red gills, bright eyes, rigor mortis, the works. You’ll probably need to find it whole, to ensure freshness, and then fillet and pin-bone it as quickly as possible. The flesh of oily fish degrades incredibly quickly. I generally put the fillets in a tub, floating in an ice-bath, then put the lot in the fridge and make the cure. Equal parts salt and sugar, some crushed fennel and coriander seed; mix together and spread out in a tray. Pin-bone the fish with your fish tweezers and place the fillets, flesh side down, in the cure. Put back in the fridge for half an hour, then wash the cure off and do any necessary trimming. A faff, yes, but it really helps to keep them in the first freshness – and as we know, there is no second freshness.
It’s plain sailing from here, anyway. Warm a saucepan of the stock, add salt, pepper, white balsamic vinegar (fine, white wine vinegar and a pinch of sugar if you must) and some very good, very ripe diced tomato. Separately warm a couple of inches of stock in a pan wide enough to take all the mackerel in one layer. When it’s just bubbling, add the fish and cook very gently for five minutes; lift the fillets out into bowls and spoon over the tomato broth. Top with herbs, and if you want more of a kick, some good, strong aioli, which of course you have in the fridge. Or if you’ve run out –
2 large egg yolks
a spoon of Dijon mustard
8 cloves of garlic, crushed with salt
juice of two lemons
extra virgin olive oil
Blitz the first three in a food processor or whisk together in a bowl. Slowly add pomace oil until it goes really thick. You DON’T have to do this in a constant stream, but it does have to be gradual. When it looks a bit too thick, mix in the lemon juice. Slowly add the olive oil until it looks and tastes right. That was easy, wasn’t it?