Roasted cod fillet with Gruyère and cheddar cheese crust

Method

1. Preheat the oven to 200C/gas 6. Place the breadcrumbs, tarragon and parsley together in a blender and add the butter and cheeses. Season with salt and freshly ground black pepper and process to a paste.

2. Spread the mixture out onto greaseproof paper, to a thickness of 1 cm.

3. Brush the cod filet with mustard and cut a piece of crust to go on top.

4. Place the fish in a roasting tray and top with the butter. Add 1 tablespoon of the wine and transfer to the oven. Cook for 4-5 minutes, until tender. While the fish is in the oven, make the sauce.

5. Place the remaining wine and vinegar into a saucepan with the tarragon stalks and peppercorns and cook for 3-4 minutes, to reduce by half.

6. Whisk the egg yolks in a bowl with a dash of water. Set the bowl over a pan of gently simmering water and add the reduced wine. Whisk over a low heat until light and fluffy.

7. Remover from the heat and slowly whisk in the clarified butter. Season to taste and add the lemon juice.

8. Fold in the whipped cream and chopped chives.

9. Place the cooked spinach on the centre of a heatproof plate and drizzle the sauce around. Place under a hot grill to glaze. Put the cooked cod on top of the spinach and serve straight away.