Ingredients
For the soused cockles
125ml/4fl oz Chardonnay wine vinegar
1 banana shallot, sliced into rings
sprig fresh thyme
2 bay leaves
5 black peppercorns
1 tsp pickling spice
450g/1lb live cockles in their shells
20 asparagus spears, trimmed, blanched, refreshed and drained
salt and freshly ground black pepper
For the brown shrimp butter
450g/1lb cooked brown shrimps in their shells
525g/1lb 3oz good-quality salted butter, clarified
1 tsp blade mace
pinch celery salt
2 pinches cayenne pepper
pinch grated nutmeg
freshly ground black pepper
squeeze lemon juice
For the poached turbot
1.2 litres/2 pints water
good splash dry white wine
1 tsp white peppercorns
large bouquet garni (1 large sprig fresh thyme, 3 celery sticks, few parsley stalks, ½ leek, 2 bay leaves and pared zest of ¼ lemon, tied together with string)
4 x 200g/7oz turbot fillets, skin removed
very finely sliced flatleaf parsley, to garnish

Method
1. For the soused cockles, pour the vinegar into a heavy-based lidded pan, add the shallot rings, herbs and spices and bring to the boil. Reduce the heat and simmer for ten minutes, then add the cockles and cover the pan with a lid. Cook for 3-5 minutes, or until the cockles have just opened - take care not to overcook them. Discard any that remain closed after cooking. Drain the cockles, reserving the sousing liquor, and remove them from their shells. Set both cockles and liquor aside and discard the shells.
2. Preheat the oven to 180C/350F/Gas 4.
3. For the shrimp butter, peel the shrimps. Reserve the shrimp meat and put the shells in a roasting tin with 125g/4oz of the clarified butter. Transfer to the oven and roast for about an hour, or until golden-brown. Leave to infuse until cool, then pass the shrimp butter through a fine sieve lined with muslin into a clean pan. Add the remaining clarified butter, the mace, celery salt, cayenne pepper and nutmeg and simmer for 15 minutes. Take off the heat and season, to taste, with freshly ground black pepper and a squeeze of lemon juice - if you've used a good-quality salted butter, it won't be necessary to add any salt. Set aside.
4. For the poached turbot, make a court bouillon. Bring the water to the boil in a large pan with a good splash of wine, the peppercorns and the bouquet garni. Lower the heat and simmer for 20-25 minutes, then remove from the heat and cover the pan with a lid. Leave to infuse until cold.
5. Strain the cold court bouillon into a pan and bring to a simmer. Gently lower in the turbot fillets, arranging them in a single layer, and poach gently for 4-5 minutes, or until cooked through.
6. While the fish is poaching, gently warm the asparagus in the reserved sousing liquor, then add the cockles and warm through for no more than 30 seconds. Season, to taste, with salt and freshly ground black pepper. Gently reheat the shrimp butter, add the peeled shrimps and gently warm through. Season, to taste, with freshly ground black pepper.
7. To serve, place a turbot fillet to the right side of each plate and place the asparagus on the left. Spoon the cockles and a little of the sousing liquor over the asparagus and sprinkle with parsley. Top the turbot with the shrimps and spoon over the shrimp butter.