Preheat the oven to 200°C.

Cut the new potatoes and tomatoes roughly into halves, then tip them into a roasting tin big enough so they can spread out and not sit on top of each other (this is key to crispy edges).

Pour over a good few glugs of olive oil, then scatter over
2–3 sprigs of thyme, a couple of pinches of salt and a good grind of pepper. Toss everything together, then put onto the top shelf of the oven. After 20 mins, remove the tin, give everything a good shake and return to the oven for another 15 mins.

Meanwhile, prep your fish. Pat the sea bass dry with some kitchen paper and rub a pinch of salt into the cavity. Cut 3–4 lemon slices and stuff into the cavity with a few thyme sprigs.

Pour the coarse sea salt into a large bowl, add 4 tbsp of water and stir together. Find a roasting tin large enough to hold the fish and tip a layer of salt into it, about 1cm thick, just under where the fish will sit and place the fish on top. Then cover the whole fish with the rest of the salt, patting down until you have encased the entire thing neatly in a salt mound.

Now back to the potatoes. Once all the liquid from the tomatoes has evaporated and everything is starting to go golden and sticky, it’s time to put in the fish. Slide the fish onto the shelf below the potatoes and cook for 25 mins.

Meanwhile, strip the cavolo nero leaves from the tough stems and chop them into strips about 4cm thick. Steam these for 3 mins, then tip into a bowl. Add a squeeze of lemon juice, the chilli flakes, a good glug of olive oil and a pinch of salt and pepper and give it a good mix.

Take out the fish and check to see if the potatoes are done. The tomatoes should have disintegrated and everything should be golden and sticky. If they aren’t ready yet, whack the oven temperature up to 220°C 7 for 5–10 mins.

Make the chilli oil: finely chop the chilli and whisk into the olive oil along with grated zest and juice of the lemon.

When everything is ready, smash the top of the salt crust with the back of a spoon and clear away all the salt. Peel off the skin and use a large knife or fish slice to serve the fish.

Once the top side of the fish is served, peel back and remove the fish bones to get at the fillet underneath. Serve the fish drizzled with the chilli oil, with the potatoes and tomatoes and cavolo nero alongside.