• a 900 g/2 lb piece of middle-cut salmon, skinned
• 85 g/3 oz butter
• 25 g/1 oz plain flour
• 1 onion, chopped
• 450 g/1 lb mushrooms, sliced
• 1 clove of garlic, crushed
• a sprig of fresh rosemary
• ½ bottle of red wine

Work 25 g/1 oz of the butter with the flour into a paste (beurre manié) and set aside. Fry the onion and mushrooms in the remaining butter. When soft, add the garlic and rosemary. Pour the fried onion mixture into a casserole, add the skinned salmon, pour the red wine over and leave to marinate for 2 hours.

Put the casserole on the hob or gas ring, bring the liquid to the boil and simmer gently for 15 minutes. Lift out the salmon and fillet it, but leave it in one piece. Keep warm. Strain the sauce and return it to the casserole. Reduce the sauce, gradually adding the beurre manie until it is the consistency of thin cream.

Put the strained vegetables from the casserole in a serving dish, place the salmon on top and pour over the sauce. Serve hot.