To make the sauce, combine the fish stock and wine in a saucepan and bring to a rapid boil. Allow the liquid to reduce by two-thirds, so that it has the consistency of a glaze. Add the cream and salt to taste, then set aside

To prepare the garnish, first make a tomato concasse by quartering the tomatoes and removing the pulp and seeds. Flatten each piece of tomato flesh and carefully remove the skin. Cut the flesh into small squares and set aside until just before serving

Peel the slices of butternut squash and celeriac, then cut them into 1cm cubes. Peel the carrots and cut them into 1cm cubes. Gently simmer the cubed vegetables in salted boiling water for 2 minutes then drain and keep warm

To make the rosti, preheat the oven to 160°C/Gas 2 1/2. Peel the potatoes and boil them in a saucepan of salted water for 4-5 minutes. Meanwhile, cut the leeks into strips, blanch in boiling water for 2 minutes then refresh in cold water

Drain the potatoes and, when cool enough to handle, grate them into a bowl. Add the leeks, then season with salt and pepper and stir in the oil

Using a round pastry cutter as a mould, shape the mixture into rosti and place on a greased baking tray. Bake for 15-20 minutes, until golden brown

To make the vegetable julienne, peel the carrots and celeriac and cut away the green of the leek so that you only use the white part. Using a mandoline, finely slice the carrots, celeriac and courgettes, then use a large knife to cut them into very fine strips. Halve the leek and cut it into fine julienne strips too

Put all the vegetable strips in a bowl then pick the leaves from the coriander and add to the bowl with a pinch of salt. Mix gently by hand and set aside

Heat some oil in a deep-fat fryer to 180˚C, also preheating the oven to 180°C/Gas mark 4

Put one handful of vegetable julienne in the hot oil for 1-2 minutes until crisp, then drain and set aside on a tray lined with a cloth or kitchen paper. Repeat seven times to give eight portions of vegetable julienne

In a frying pan with a little oil, fry each fillet of sea bass skin-side down for 1 minute, then transfer all the fish to the oven on 100% steam setting and cook for 2 minutes. As an alternative, place the fish in a pan or wok steamer for the same cooking time above

Gently warm the sauce. Remove the seeds from the vanilla pod and add them to the sauce with the coriander

Put your rosti on serving plates and top with the sea bass. Put a nest of julienne vegetables on top of each fish fillet. Sprinkle the tomato concasse and the cubed vegetables around the plate then spoon over the sauce to finish