Radicchio and Leek Lasagne

2 Small Heads Radicchio di Treviso 1 Knob of Butter	Cut off the bases of the Radicchio, and separate the leaves. Wash thoroughly, and dry in a salad spinner. Melt the butter in a saucepan, and gently fry the radicchio for a few minutes, until it becomes fragrant and begins to wilt.
6 Sliced Spring Onions 2 Sliced Leeks Salt, to taste	Add the leeks and spring onions to the saucepan, and cook until the leeks soften, adding the lid to the saucepan if necessary. Once soft, add salt to taste.
1l Béchamel Salt Nutmeg Pepper	Prepare some Béchamel, and season to taste with salt, pepper and nutmeg
250g Lasagna Pasta Sheets	Soak each lasagna sheet in a bowl of boiling water for one or two minutes before using.
150g Parmesan 100g Walnuts	Coarsely grate the parmesan and crush the walnuts. Cover the bottom of a rectangular baking dish with bechamel and then lay the first layer of pasta. Spread some bechamel on top of the pasta and add some of the vegetables. Cover with crushed walnuts and a generous amount of coarsely grated parmesan. Repeat for three or four layers (for a tray of 30x20 cm), making sure that the last layer is completely covered by bechamel and cheese. Bake for 25 minutes at 220°C ( 200°C fan).