Make the Bolognese sauce by adding a good lug of olive oil to a large casserole pan over a medium heat. Add the bacon and fry until golden, then add the onions, garlic, carrots, mushrooms and celery, then add the thyme leaves and cook for around 10 minutes, or until softened and lightly coloured, stirring regularly.
Add the minced meat and tinned tomatoes followed by 1 tin of water, the wine, and a good pinch of salt and pepper and the basil stalks. Bring to the boil, then reduce the heat to low and simmer with a lid on for around 1 hour, stirring every now and again. Remove the lid, turn the heat to high and cook for a further 20 to 30 minutes, or until thickened and reduced. Stir regularly and add a splash of water to loosen, if needed.
Meanwhile, fill a large pan with salted boiling water, add a drizzle of olive oil, then blanch your pasta sheets for 3 to 4 minutes – it’s best to cook them in batches. Drain the sheets then carefully pat them dry with kitchen paper and put to one side until needed.
Preheat the oven to 200°C/400°F/gas 6. Add the onion, milk, parsley, nutmeg and peppercorns to a pan over a medium heat and 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 one 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 and stirring through most of the Parmesan. Season to taste.
Remove the Bolognese from the heat, then tear in and stir through the basil leaves. Have a taste of the sauce and season with a little more salt and pepper if needed.
To assemble the lasagne, spoon a third of the Bolognese into the bottom of an ovenproof dish (roughly 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 and the remaining Parmesan. Drizzle with olive oil, cover with tin foil, then place in the oven for 20 minutes. Remove the 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. Serve with a lovely fresh green salad.