Spring risotto (risotto primavera)

Bring the vegetable stock and parmesan rinds to the boil in a large pan and then immediately turn down to a simmer.

Heat a separate pan with boiling, salted water. Once boiling, add the leeks and blanch for a few minutes. Remove with a slotted spoon and transfer to a bowl of iced water. Drain once cool and set aside.

Repeat the blanching process with the carrots, broad beans, peas and asparagus, each time refreshing in iced water and draining again. Set all the blanched vegetables aside.

Heat the olive oil and butter in a pan and add the onion. Fry for a few minutes and then add the garlic and thyme. Cook for a further 10 minutes, or until the onions are softened, but not browned.

Stir in the rice and fry for about a minute, until the rice is translucent. Add the wine and simmer until the liquid is absorbed by the rice.

When the wine is all absorbed, add a ladleful of the hot stock, taking care not to add any of the parmesan rinds to the risotto. Keep stirring until all the liquid has been absorbed. Keep adding the stock in the same way, stirring often, until the stock is used up and the rice is cooked al dente (that is, tender but still with a slight resistance to the bite) - this will take about 15-20 minutes.

Stir in the blanched vegetables and mascarpone. Add most of the parmesan, a squeeze of lemon juice and the remaining butter. Add a touch more stock to loosen if necessary.

Leave the risotto to rest in the pan for a few minutes and serve in bowls with the remaining parmesan scattered over.