Fillets of bass with vanilla butter vinaigrette

Ingredients

100g/4oz unsalted butter
4 sea bass fillets, weighing about 100g/4oz each, skinned
½ vanilla pod
50ml/2fl oz vermouth
2 tsp white wine vinegar
1 shallot, peeled and halved
150ml/5fl oz fish stock
25g/1oz peeled, seeded and diced tomato
1 tbsp coarsely chopped fresh chervil
salt and freshly ground black pepper

Method

1. Clarify the butter by melting it gently in a small pan, then skimming off any froth and pouring off the clear liquid into another pan, leaving behind the butter solids which will have collected at the bottom.
2. Brush both sides of the sea bass fillets with a little of the clarifed butter and season with salt and pepper.
3. For the vinaigrette, split the vanilla pod open lengthways, scrape out the seeds with a small tsp and then chop the pod very finely.
4. Put the seeds and pod into a small pan with the vermouth, vinegar and shallot, bring to the boil and boil for a few minutes until reduced to about 1 tbsp.
5. Add the fish stock and boil once more until reduced to about 45ml/3 tbsp.
6. Remove the shallot halves, then add the remaining clarified butter, plus the tomato, chervil, ¼tsp of salt and 6 turns of the pepper mill. Keep just warm over a very low heat.
7. Heat a lightly oiled cast-iron ribbed pan until very hot. Cook the fish fillets, skin-side down, for 1 minute, pressing down on top of each fillet in turn with the back of a fish slice to help mark them with the lines of the griddle. Turn over and cook for 30 seconds of the other side.
8. To serve, put the fish fillets of four warmed plates and spoon the vinaigrette to the side.