Truffled celeriac and cavolo nero lasagne

First, cook the celeriac. Put it in a deep lidded pan with the mushrooms and shallot, and cover with 450ml of the milk. Season with salt and bring up to the boil, then turn down to a simmer. Cover and cook for 20-25 mins or until the celeriac is fork-tender and can be puréed. Set aside to cool.

Meanwhile, make the pesto. Bring a pan of salted water to the boil and blanch the cavolo nero until wilted. Drain and squeeze out the excess moisture, then put into a food processor with the pine nuts, parmesan, lemon juice, garlic, rosemary, olive oil and 4 tbsp of water. Blitz until you have a spoonable pesto.

Now it’s cool, purée the celeriac until very smooth and creamy using a blender or stick blender. To make the béchamel, melt the butter in a large pan with a good grating of nutmeg, and scatter over the flour, working it in with a wooden spoon to form a roux. Slowly pour in the rest of the milk, whisking to emulsify into the roux, and gradually adding until it’s all combined. Cook the sauce, stirring, for 6-8 mins or until smooth and creamy, then pour in the puréed celeriac and whisk to combine. Taste for seasoning and adjust with a little more salt and pepper, then add the truffle oil to your taste.

Heat the oven to 190C/170C fan/gas 5. Grab an ovenproof lasagne dish (about 25cm x 20cm) and cover the bottom with the dry lasagne sheets. Ladle over enough béchamel to cover the bottom and smooth it out, then add a couple of spoonfuls of the pesto and swirl through. Top with a layer of sliced mozzarella and repeat with the lasagne sheets, béchamel, pesto and mozzarella until it’s all used up, finishing with a layer of béchamel. Grate over a layer of extra parmesan and drizzle with olive oil, then bake in the oven for 40 mins until the pasta is cooked through and tender.

Remove from the oven and allow to settle for at least 10 mins before serving in slices. I like it served with a sharply dressed bitter leaf salad.