In a small saucepan, heat the milk with the next seven ingredients. Bring very slowly to a simmer and leave to cool. Strain into a jug or bowl, pressing to squeeze out all the liquid. In another saucepan melt the butter and sweat the leek, covered, for 5 minutes. Add the flour and cook gently for a further 5 minutes. Gradually add the strained milk, whisking or stirring hard to avoid lumps, and the wine. Add the cream, and salt to taste, cool, and pour over the fish mixture. Gently stir in the herbs and transfer the lot to an oblong or oval gratin dish, about 25.5cm ∞ 20.5cm. Smooth the top.
© 2001 Stephen Bull. All rights reserved.