Season the trout fillets on the flesh side with salt and freshly ground black pepper.
Heat a frying pan until hot then add half the butter and the trout, skin side down. Cook the trout for two minutes on each side then remove from the pan.
Place the trout on a chopping board, peel off the skin then cut each fillet into 3-4 pieces and keep warm.
Heat a frying pan until hot then add the remaining butter, the shallots and star anise and cook gently for one minute.
Add the carrots, leeks, potatoes and turnips and continue cooking for another two minutes.
Add the white wine and stock and bring to a simmer. Cook until the liquid has reduced in volume by half. Add the clams and mussels to the pan with the curly kale, return to the boil and cover with a lid.
Cook for 2-3 minutes until the shellfish has opened and the vegetables are just tender. Discard any clams or mussels that haven’t opened. Add the chives and chervil and season with salt and freshly ground black pepper
To serve, place the trout into warmed soup plates, spoon over the shellfish and vegetables and ladle the broth over the top.