Preheat the oven to 220C/450F/Gas 7.
Cook the beans for 15-20 minutes in 1litre/1¾ pint of water and the chicken stock with the bouquet garni. Cook gently and do not boil - otherwise the beans will break up.
Heat a saucepan with a lid and cook the clams with the white wine and one of the shallots, until the clams open, then drain in a sieve, reserving the juice. Pick the meat from the clams and discard the shells.
Line a small heavy-based casserole dish with the three types of seaweed (reserve a few pieces of dulse for the garnish).
Heat a frying pan with a little of the butter and fry the fish on one side until golden-brown. Turn over, remove from the pan and place into the pan with the seaweed.
Into the same hot pan you used to fry the fish, put a good sized spoonful of butter and the other finely chopped shallot, capers, half the chopped dill, clam juices and a few drops of lemon juice. Bring up to the boil and then pour the mixture over the fish. Place the lid onto the pan and cook in the oven for 5-6 minutes.
Add the fennel shavings (reserving the diced fennel), the remaining chopped dill and fennel tops if you have them. Season with salt, lemon juice and olive oil and add half of the reserved dulse. Set aside.
Place half of the coco beans in a blender and purée; finish with a few drops of olive oil, some butter (reserve a few knobs) and the lemon juice. Drain the remaining coco beans, add the diced fennel and a little chopped dulse.
Remove the fish from the casserole dish and reserve. Strain the juices from the seaweed and add a splash to the whole coco beans. Place the beans back on the heat and bring to the boil, add a couple of knobs of butter and stir until the beans are glazed with butter. Add the reserved clam flesh. Taste and add a few more drops of lemon juice if necessary.
To serve, place a good-sized spoonful of purée in the centre of each plate, make a well with your spoon, place the beans on top with the fish and a small amount shaved fennel salad.