1 whole turbot (about 2kg/4lb 8oz), cleaned and prepared, plus extra bones from your fishmonger
1 tbsp vegetable oil
1 bulb fennel, thinly sliced
½ leek, thinly sliced
100g/3½oz bonito flakes
1 stick lemongrass, bashed and finely chopped
150g/5½oz kombu, soaked in cold water
2 sheets nori
100ml/3½fl oz soy sauce
150ml/5fl oz rice wine vinegar
1 tbsp butter
1 garlic clove, finely chopped
200g/7oz broad beans, double podded
2 courgettes, diced
4 courgette flowers
30g/1oz salty fingers or samphire
1 lemon, juice only
2 finger limes, sliced
salt and freshly ground black pepper
Preheat the oven to 220C/200 Fan/Gas 7.
Season the turbot with salt and pepper and drizzle with the oil then place in a roasting pan and roast for 30 minutes or until cooked. Test whether the fish is cooked by cutting down on to the backbone at the thickest part and checking that the flesh has turned white right through. Keep warm.
Meanwhile, roast the extra fish bones in a separate roasting tin alongside the turbot for 30 minutes.
To make the dashi, place the roasted bones, fennel, leek, bonito flakes, lemongrass, kombu and nori, soy sauce and rice wine vinegar in a large saucepan with 1 litre/1¾ pints water. Bring to the boil and simmer for 10–20 minutes. Strain the liquid into a separate pan and keep warm.
Heat half of the butter in a sauté pan over a medium heat, add the garlic, broad beans and courgettes and cook gently for 5 minutes. Season with salt and pepper.
Heat the grill to its highest setting and grill the courgette flowers for 2–3 minutes.
Warm the remaining butter in a frying pan and add the salty fingers or samphire and warm through gently. Season with a little lemon juice.
To serve, place a courgette flower in the bottom of each dish and divide the broad beans and courgettes between the bowls. Top with some turbot without the skin or bones, the salty fingers or samphire and finger limes, then pour over the dashi.