I adore this version. I think it must have fresh (not dried) pasta sheets and I cheat and use good shop bought pesto.
Nigel Slater?s Mushroom Lasagne
As with any dish of this kind, quantities are a bit vague, and really a function of how big your dish is or how big your appetite. It doesn?t matter if you?ve got a bit less pesto, or if you end up with extra layers of pasta to fit everything in ? cooking time in the oven is really forgiving (anything from 30 to 55 minutes) as long as the individual components are cooked properly to begin with. Just make sure it?s bubbling and brown and it will be great, and of course you could always prepare it in advance and cook it from cold for longer.
For the bechamel:
1 litre whole milk
3 heaped tablespoons flour
45g butter
For the pesto:
60g pine nuts
2 big bunches basil, giving about 4 handfuls of leaves
4 tablespoons grated parmesan
2 tablespoons olive oil
2 cloves garlic, peeled
For the sautéed mushrooms:
A thick slice of butter
1 large onion, chopped
2 cloves garlic, thinly sliced
500g mushrooms, sliced
1 handful chopped parsley
10g porcini mushrooms
2 tablespoons grated parmesan
Lasagne sheets, preferably the type that doesn?t need precooking to make your life easier
Preheat the oven to 180°C.
Start with the mushrooms. Sauté the onions and garlic in the butter over a medium heat for around 20 minutes until definitely soft and transparent. Meanwhile cover the porcini in around 100ml of boiling water. After the onions have softened, add the mushrooms, porcini with their cooking water, parsley and a couple of tablespoons grated parmesan. Cook with the lid half on, allowing quite a lot of moisture to escape, for around 20 minutes, until the mushrooms are coloured and nice and soft.
During this sauté time, you can make the pesto by putting all the ingredients in a food processor, and processing it until it forms a paste. Don?t worry too much about the consistency (too dry, too wet), as it will blend into the bechamel during cooking.
Prepare the bechamel by melting the butter in a saucepan, and then cooking in the flour as a roux for a few minutes. Remove from the heat and whisk in the milk gradually until it has all been incorporated. Return to the heat and cook, stirring fairly assiduously, for 10 to 15 minutes until glossy and thickened.
Now my favourite bit: find an ovenproof dish around 20×25cm. Ladle in a bit of the bechamel to cover the bottom, then put a layer of lasagna sheets. Follow this with half the mushroom mixture (if it is still very liquidy, then lift out just the mushrooms with a slotted spoon). Follow with a quarter of the bechamel. Now a layer of pasta, the rest of the mushrooms, another quarter of the bechamel, and another layer of pasta. Spread the pesto over this final pasta layer, and top with the rest of the bechamel. Give a good grating of parmesan over the top, and bake for around 30-40 minutes until there are browned bits on top.