There are just two ingredients in this dish - the seabass and the salt. But be sure and order your fish well in advance. Trying to get hold of a seabass on Christmas Eve will be about as easy as hitching a ride on Santa's sleigh. And two smaller seabass will serve you better than one large one. Apart from frugality - the weight of its belly and the waste involved - there's nothing more annoying than having to cut off its tail or head to fit it into the oven. Two smaller silvered fish lying gill to tail fin are just as alluring to behold.
From here, the first step is to concoct a paste with a mountain of sea salt and water, scatter half of it over the base of a baking tray, lay the fish on top and smother so that only the heads and tails protrude from the white crystal shell. After baking in a fierce oven, the salt crust hardens into a crisp pod, sealing in the juices. Once cracked and broken off, you are left with the most succulent flesh imaginable, imbued with the purest flavour of seabass that is perfectly seasoned, and not in the least oversalted.
The same theory can be extended to a variety of whole fish, including red snapper, salmon and turbot, but I have a personal soft spot for seabass. A buttery red wine and shallot sauce with a dollop of creamy champ is all that is needed in addition. If you do feel the need to pass veg around, then a smattering of sauteed wild mushrooms or a little wilted spinach would make fitting accompaniments. For me, Christmas dinner lies firmly with a tradition of red wines, and I would choose a soft red such as a Sancerre or a light Burgundy to accompany it.
Some recipes for baking in salt suggest you can get away with cheap table salt, but I feel quite strongly that it has to be a pukka sea salt such as Maldon, which I would rate over and above the wet French sel gris for the job. Recently, though, Maldon has been joined by a Welsh competitor called Halen Mon or Anglesey Salt. This is the creation of David Lea-Wilson, who until a few years back, was struggling to make a year-round living from his public aquarium.
With a firm belief in the unusually pure seawater from the Gulf Stream that surrounds him, he decided to capitalise on it. Producing Halen Mon took several years of experimentation and lab analysis not only of his own carefully harvested crystals but of all the other salts on the market, too, including those from the Mediterranean: "We looked carefully at sel gris, which has a certain trendy following, and our deduction is that the colour is not so much from the seawater as from the special clay pans used in that area." He reckons it's more polluted than British salt.
My initial introduction to Halen Mon was not entirely good. In the process of seasoning a salad of flageolet beans I had picked up in Caen market that weekend, the top came off the pot and the entire contents fell onto the salad, spilling over the edge of the worksurface and showering my 15-month-old son, Louis, who was standing directly in front of my feet gazing up mouth open. I can at least assure you on account of this, that it is not only free-flowing but dissolves with efficient speed. I couldn't rate Halen Mon over and above Maldon - they're both superb salts and either will do nicely.
Seabass baked in salt, serves 6
1.5kg sea salt
2 x 1kg seabass, gutted, and unscaled
Heat the oven to 230C fan oven/240 or 475F electric oven/Gas 9. Tip the salt into a large bowl, pour over 425ml water and stir until the salt is uniformly wet. Lay a sheet of foil on the base of a baking tray large enough to hold the seabass side by side - I use my grill pan. Scatter over half the salt, levelling it into an even layer. Lay the seabass top to toe and cover the fish with the remaining salt, leaving the head and tail uncovered. Bake for 30 minutes, by which time the fish should be just cooked. Take it out of the oven, lift off the upper crust of salt and carefully remove the fish to a serving plate. Fillet it by cutting along the backbone with a sharp knife and easing the flesh off. It makes life easier to leave the skin in place although you can't actually eat this. Spoon over the sauce and serve.
Red wine shallot sauce
You can make this sauce while the fish is baking, although the base can be prepared in advance and you can whisk in the butter at the last minute.
3 shallots, peeled and finely chopped
3 thyme sprigs
425ml red wine
225g unsalted butter, diced
Sea salt, black pepper
Place the shallots, thyme and red wine in a small saucepan and reduce until it's syrupy and there are only a few tablespoons left; this will take 20-30 minutes. Discard the thyme and gradually whisk in the butter, working on and off the heat as necessary. At no point should the sauce simmer; season it about halfway through