- at least 500g/1lb 2oz fresh porcini, or other boletus (ideally twice that quantity)
- 275g/10oz parma ham, sliced very finely
- white lasagne sheets, ideally fresh, but dried can be used (enough to make at least 3 layers in an 20cmx25cm/8x10in baking tray)
- at least 250g/9oz fresh parmesan
- truffle oil (optional)
- butter
- 500ml/17fl oz hot milk
- 50g/2oz butter
- 50g/2oz plain flour
- pinch nutmeg
- salt
- freshly ground black pepper
- To make the bé chamel sauce, mix the flour with the melted butter in the pan and cook it for a few minutes. Add the hot milk by degrees and stir to thicken. Bring to the boil and allow to simmer for just a minute. Season with nutmeg, salt and pepper.
- Grate half the parmesan and stir into the bé chamel. The finished bechemel should be a thick pouring consistency. Add a little more hot milk if necessary.
- To prepare the rest of the ingredients, slice the whole boletus into large but very thin slices. If you are using dried lasagne of the kind that requires pre-cooking, then cook according to the instructions. Scrape the rest of the parmesan into shavings with a large knife blade or potato peeler.
- Pour a small amount of the bé amel onto the bottom of an ovenproof dish. Put a layer of white lasagne on top followed by a layer of thinly-sliced ceps, a layer of parma ham and a layer of slivers of parmesan. Season with a few drops of truffle oil.
- Then pour over a layer of béamel and repeat the layers. You can make as many layers as you have ingredients, or space for, but finish with a layer of béamel sauce, some grated parmesan and a few knobs of butter.
- Bake for around 20-30 minutes in a fairly hot oven (190C/375F/Gas 5) until nicely browned on top.