Potted brown shrimp and devilled crab claws

Ingredients

For the devilled powder
200g/7oz finely sliced onions
1 garlic clove, peeled
2 red chillies
2 tbsp capers in vinegar, drained and any excess liquid squeezed out
25g/1oz mustard seeds
salt
For the devilled butter
250g/9oz unsalted butter
1 garlic clove, peeled, roughly chopped
2 tsp salt
40g/1½oz English mustard
2 tsp sherry vinegar
20ml/1fl oz Worcestershire sauce
2-3 drops Tabasco sauce
For the crab and brown shrimp reduction
2 tbsp vegetable oil
500g/1lb 2oz crab shells and brown shrimp shells (from the potted brown shrimp and crab, below), crushed
1 onion, peeled and quartered
2 large carrots, peeled and quartered
1 celery stick, chopped into four equal pieces
3 cloves garlic, peeled
2 fresh bay leaves
1 sprig fresh thyme
4 black peppercorns
1 tbsp tomato purée
200ml/7fl oz white wine
200ml/7fl oz brandy
water, to cover
For the potted brown shrimp and crab
200g/7oz brown shrimp, shells removed and reserved for crab and brown shrimp reduction, above
80g/3oz picked crabmeat (reserve shells for use in crab and brown shrimp reduction, above)
110g/4oz devilled butter, at room temperature (above)
crab and brown shrimp reduction, to taste (from above)
To serve
24 brown shrimp, heads on
1 tbsp unsalted butter
8 crab claws
2 tsp crab and brown shrimp reduction (see above)
devilled butter (see above)
wild herbs (chickweed, bitter cress, wood sorrel, wild chervil)

Method

1. Preheat the oven to 75C/165F, or to its lowest setting.
2. For the devilled powder, mix together all of the devilled powder ingredients in a bowl, then spread out evenly over an oven tray lined with greaseproof paper. Place into the oven to dry out for 12 hours, or until all of the ingredients are dry and crisp.
3. Transfer the devilled powder ingredients to a food processor and blend to a fine powder. For every 50g/2oz of the powder, mix with one teaspoon of salt. Keep the mixture in an air-tight container until needed (you will not need all of the devilled powder for this recipe).
4. For the devilled butter, place all of the devilledbutter ingredients into a food processor and blend until smooth. Scrape the butter into a bowl and set aside until needed.
5. For the crab and brown shrimp reduction, heat the oil in a large heavy-based pan until smoking, then fry the shellfish shells for 3-4 minutes, or until golden-brown. Add the onion, vegetables, garlic, herbs and peppercorns to the pan and fry for a further 3-4 minutes, or until the vegetables are golden-brown. Stir in the tomato purée, then deglaze the pan with the white wine and brandy, scraping up any browned bits from the bottom with a wooden spoon.
6. Cook for 5-6 minutes, or until the liquid has reduced by half, then pour in enough cold water to cover the shells halfway. Bring back to the boil, skimming off any scum that rises to the surface. Reduce to a simmer and cook for 45 minutes.
7. Pass the stock through a sieve, pressing as much as you can through, then strain again through a fine sieve. Return the stock to a clean pan and simmer for 10-15 minutes, or until the stock has reduced to a thick and sticky consistency. Cool to room temperature, then chill in the fridge until needed.
8. For the potted brown shrimp and crab, mix all of the shrimp and crab ingredients together in a bowl, then transfer to a vacuum pack bag, being sure to reserve some crab and brown shrimp reduction to serve the dish. Seal the bag and place into a water bath set at 19C/65F for 12 minutes.
9. To serve, thread the brown shrimp evenly onto four soaked wooden skewers. Melt the butter in a frying pan until foaming, then fry the crab claws for 6-8 minutes, or until just cooked through, adding the brown shrimp skewers during the last five minutes of cooking. Add the crab and brown shrimp reduction to the pan along with the remaining devilled butter. Baste the crab claws and shrimp skewers with the melted butter mixture.
10. Divide the potted brown shrimp and crab mixture evenly among four serving plates, then arrange two crab claws and a shrimp skewer on top of each pile of potted crab and brown shrimp. Garnish with the wild herbs, then dust with the devilled powder and serve.