Start by bringing the potatoes to the boil with a generous amount of salt and water in a pan. Cook until the potatoes are al dente. Pour the potatoes through a sieve and set aside. Cut the fennel into slices about half a centimetre thick, rub the slices with a little vegetable oil and season with salt. Cut the carrots in half and also rub with oil and salt. Grill the fennel slices, carrots and potatoes separately over the binchotan, until they begin to colour. Grill the sea bass fillet over the hot binchotan until the skin is nice and crispy. Turn the fillet over and let it rest next to the fire. Serve the vegetables, sea bass fillet and potatoes and add heat vegetable stock or dashi stock.