Method
Melt 25 g of the butter, brush the cut surface of the squash with it and pour the rest into the well in the squash. Place a sage leaf into the well, wrap the squash un foil and bake in an oven pre heated to 170 degrees C for1 hour, or until completely tender. Remove from the oven and set aside to cool. When warm, remove the sage leaf, scoop out the squash and any butter, transfer to a small pan and crush into a textured mass. Season with salt, pepper and a pinch of sugar if necessary. Place the rice into a pan, cover with an excess of water, season with salt and cook for 30 minutes or until tender. Drain and set aside at room temperature. Dice the pickled walnuts.
To Serve
Place a large non stick pan over a medium heat. Once hot season the fish, put a splash of vegetable oil into the pan and add the fish - skin side down. Turn up the heat and cook until crisp - about 2 minutes. Add 25g butter to the pan, let it melt, add the sage leaves and trompettes, turn the fish over, cook for a further minute or so, add the stock and remove the pan from the heat. Add the pickled walnuts. Heat the rice and squash. Place a spoonful of each neatly onto a plate, sit the fish onto the squash and spoon the juices and pickled walnuts, trompettes and sage leaves over the top.