For the Bolognese, trim, peel and finely chop the onions, garlic, carrots and celery, then clean and roughly chop the mushrooms.
Pick the thyme and basil leaves, finely chopping the basil stalks, then finely slice the bacon.
Heat a good lug of oil in a large casserole pan over a medium heat, add the bacon and fry until golden, then add the onions, garlic, carrots, celery, mushrooms and thyme and cook for around 10 minutes, or until softened and lightly coloured, stirring regularly.
Add the minced meat, tinned tomatoes, breaking them up with a wooden spoon, and 1 tin’s worth of of water.
Pour in the wine, then add a good pinch of sea salt and black pepper and the basil stalks. Bring to the boil, then reduce the heat to low and simmer with a lid ajar for around 1 hour, stirring occasionally.
When the time’s up, remove the lid, turn the heat to high and cook for a further 20 to 30 minutes, or until thickened and reduced, stirring regularly and adding splashes of water, if needed.
Meanwhile, fill a large pan with boiling salted water, add a drizzle of oil, then blanch your pasta sheets for 3 to 4 minutes – it’s best to cook them in batches. Drain, then carefully pat dry with kitchen paper and put aside until needed.
Preheat the oven to 200°C/400°F/gas 6.
For the white sauce, peel and finely slice the onion, then place in a pan over a medium heat with the milk, parsley, a few scrapings of nutmeg and the peppercorns. Gently bring to the boil, then strain into a jug.
Melt the butter in pan over a medium-low heat, then mix in the flour adding and stirring in 1 splash of milk at a time until you have a smooth white sauce. Bring to the boil, then simmer for a couple of minutes before removing from the heat. Finely grate and stir through most of the Parmesan, then season to taste.
When the time’s up, remove the Bolognese from the heat, tear in and stir through the basil leaves and season to taste, if needed.
To assemble the lasagne, spoon a third of the Bolognese into the bottom of an ovenproof dish (25cm x 30cm), then follow with a layer of lasagne sheets and a third of your white sauce. Add another layer of Bolognese and repeat the process twice more, finishing with a layer of white sauce.
Finely grate over the remaining Parmesan, drizzle with oil, cover loosely with tin foil and place in the oven for 20 minutes.
Remove the tin foil and cook for a further 30 minutes on the grill/fan setting (at the same temperature), or until golden brown and bubbling at the edges. Delicious served with a seasonal green salad.