Preheat the oven to 170°C fan.

Pierce the celeriac with a fork all over about 40 times and place on a parchment-lined baking tray.

Mix the oil and 3 teaspoons of flaked salt, then rub the celeriac generously with the oil mixture.

Roast for a minimum of 2¼ hours, or up to 2¾ hours, depending on the size of your celeriac, basting every 20 minutes or so, until the celeriac is deeply browned, soft all the way through and oozes a celeriac caramel.

Leave to rest for 15 minutes, then cut widthways into 2½cm-thick steaks, brushing each cut side with the oil and caramel left on the tray.

Put the first seven ingredients for the sauce and ¼ teaspoon of flaked salt into a small saucepan on a medium heat.

Cook for about 6 minutes, swirling the pan until the shallots have softened and the butter has melted and become golden and caramelised.

Add the capers, herbs and a very generous grind of pepper and continue to cook for 1 minute, then remove from the heat.

Turn the oven to its highest grill setting.

Arrange the celeriac steaks, spaced apart, on a large, parchment-lined baking tray big enough to fit the slices in a single layer.

Grill the steaks on the top shelf of the oven, until they are golden-brown on top, 6–8 minutes.

Turn the oven off, keeping the tray warm in the oven until you’re ready to serve.

Return the sauce to a medium heat and gently cook for a minute, then add the cream and lemon juice.

Swirl for another 2 minutes or until warm, but don’t mix it too much – you want the sauce to be split, not emulsified.

Pour the sauce on to a large platter with a lip and arrange the celeriac steaks on top.

Sprinkle the steaks with a little flaked salt and black pepper, and serve.