Turbot is a regal fish that comes at a suitably regal price. But then it is Christmas. Note: avoid North Sea turbot, as stocks are depleted. And be aware that the hollandaise is made with uncooked egg yolks.

Serves up to 6, depending on greed

2kg whole turbot, gutted and prepared for baking (with the skin on the dark side cut through close to the fins; ask the fishmonger to do this for you)
Salt and pepper
Butter
1 bay leaf
Handful of parsley
Few sprigs of thyme
Few slices of lemon
150ml dry white wine

For the hollandaise

225g butter
1 bay leaf
4 egg yolks
1½ tbsp lemon juice
Salt and pepper

Preheat the oven to 200C/400F/Gas Mark 6. Season the fish on both sides. Grease the bottom of a large roasting tin with a little butter and place the turbot on top, dark skin facing up. Put the bay leaf and parsley in the cavity with a sprig of thyme and a slice of lemon. Pour over the wine and dot with a few more bits of butter, a couple of lemon slices and a sprig or two of thyme. Cover the fish loosely with greaseproof paper and bake for 25 minutes.

Test the thickest part with a skewer. If done, it should slip through without resistance. If not, give it 5 minutes more. A 2kg fish shouldn’t take more than 35 minutes.

Meanwhile, make the hollandaise. Fill the container of an electric blender with hot water. Melt the butter in a pan with the bay leaf until bubbly and properly hot – but don’t let it brown. Remove the bay leaf. Empty the blender and shake dry. Tip in the egg yolks and lemon juice, then mix for about 1 minute until frothy. Now, with the motor running, drizzle the hot butter into the yolk mixture in a thin, steady stream. The sauce will gradually thicken. Stop before you get to the white bits at the bottom of the pan. Season.

The sauce is best served immediately, but you can keep it warm in a bowl suspended over a pan of just-boiled water for about an hour – but the bowl mustn’t touch the water. Keep an eye on it and whisk occasionally. If it decides to split, quickly whisk in a splash of boiling water; it should come back together. Even easier is to have ready a vacuum flask filled with boiling water. Empty it thoroughly, then pour in the hollandaise to keep warm.

Bring the fish to the table in its baking tray. To fillet, gently peel back the dark skin with a knife. Push the frill of bones from around the side, slit the fish along the central backbone, then lift off the top fillets. Release the backbone at the tail and gently lift off. Remove the bottom fillets.

Serve with a jug of the hollandaise. Some buttered spinach on the side wouldn’t be bad – and, though I hate to say it, a few unseasonable new potatoes.

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