• 4 cod cutlets, 6–8 oz / 170–230 g each
• salt
• freshly ground black pepper
• juice of ½ lemon or orange
• 1–2 tbsp extra virgin olive oil

Sauce

• 3 garlic cloves, peeled
• 1 oz / 30 g parsley, roughly chopped
• 2 tsp lemon or orange juice
• 1 tsp Dijon mustard
• 4 tbsp extra virgin olive oil
• salt
• freshly ground black pepper

Lightly season the fish, squeeze on some lemon or orange juice, and brush with olive oil. Allow it to stand for 10–15 minutes while you start making the sauce. Cut the garlic cloves into two or three pieces and put in a small saucepan with 2–3 tablespoons water. Simmer until the garlic is tender. Stir in the parsley, and let it cook for just 3—4 minutes, retaining its bright colour but becoming tender. Allow to cool slightly, and then blend until smooth. Sieve into a bowl set over a pan of hot water or into bain-marie. Stir in the fruit juice and mustard, and keep the sauce warm while you cook the fish. Using a heavy, lidded sauté or frying pan, cook the fish over a low heat for about 5 minutes, depending on thickness; a little longer may be required. The fish will be lubricated enough to cook in its own juices without burning. Strain fish juices into the parsley purée. Remove the fish from the heat, but keep it covered and in a warm place. Gradually whisk the olive oil into the purée, drop by drop, so that it will emulsify and thicken like a hollandaise sauce. Season lightly, and serve with the fish. If the sauce separates, don’t worry; it still tastes very good, even though it might not look quite as it should.