It can be prepared in advance, and then put into the oven about 20 minutes before you’re ready to eat.

• First, prepare the sauce. Melt the butter in a saucepan and stir in the flour, mustard, and cayenne. Stir over low heat for 2–3 minutes. Slowly whisk in the milk until smooth. Simmer, stirring, for 5 minutes to cook out the flour. Remove the pan from the heat and stir in the cheeses until they have melted and the sauce is smooth. Transfer to a bowl and let cool. Once cooled, stir in the crème fraîche. Taste and adjust the seasoning.

• To prepare the filling, melt the butter in a pan and add the spinach, some seasoning, and a light grating of nutmeg. Cook over high heat until the spinach has wilted, then tip into a colander set over a large bowl and let cool. Return the pan to the heat and add the olive oil, mushrooms, and some seasoning. Sauté the mushrooms until tender and any juices released have evaporated, 3–4 minutes. Transfer to a large bowl and let cool. Give the spinach a light squeeze to remove excess moisture and add to the mushrooms. Stir in the ricotta and Parmesan. Taste and adjust the seasoning.

• Roll the cannelloni one at a time: Place a lasagne sheet on a cutting board. Spoon 2 tablespoons of filling along one end, leaving a bit of space at both edges, and roll up. Place on a tray, joined-side down. Repeat with the remaining pasta and filling.

• Preheat the oven to 425°F. Spread half the cheese sauce over the bottom of a large baking dish and arrange the cannelloni in a single layer on top. Spread the remaining sauce over the cannelloni to cover, then sprinkle with the Parmesan. Bake until the topping is golden brown, 15–20 minutes. Bring to the table and serve at once.