Add a tiny splash of olive oil to a large, high-sided pan on medium-high heat. Peel the casings off the sausages and crumble them into the pan. Fry for about 5 minutes until they're browned but not fully cooked, then add the garlic and pepper flakes. Fry another 2 or 3 minutes. Make sure the garlic doesn't brown or burn.

Stir the tomato paste into the pan and let cook for 2 minutes. Deglaze with the wine. Once the wine's mostly cooked off, add the passata. Season with salt and several grinds of black pepper, then cover and turn the heat down to low. Let simmer for 30 minutes, then take the pan off the heat and set aside until assembly.

Melt the butter in a medium pot over medium-low heat. Add the flour and whisk for about 5 or 6 minutes until the roux is a light brown colour. Pour in the milk. The bechamel will seize; don't worry about it. Whisk until it smooths out and thickens a bit more than heavy cream. This will take about 10 minutes. Whisk in a small pinch of nutmeg and another of salt, then take the pot off the heat. Cover with cling film to prevent a skin forming. Make sure the plastic touches the surface.

Prep the fresh mozzarella by cutting it into 1/2 cm slices, then laying those on a paper-towel lined plate. Put a second layer of paper-towel on top, then a large pot on top of that to weight it down.

Put the basil leaves, garlic, pine nuts, and lemon juice in your food processor. Add a pinch of salt and a few tbsp extra virgin olive oil. Pulse a few times and check the consistency. Add more olive oil as needed, and continuing pulsing until you get a a smooth, slightly chunky sauce.

Preheat your oven to 350 F. Start assembly by smearing the bottom of an 18 x 24 cm baking dish with a bit of meat sauce. Lay noodles on top of that. Next, spread on more meat sauce, and cover that with a layer of spinach leaves. Pour some bechamel on top of that, then spread on another layer of noodles and repeat the sauce/spinach layers. Be sure you reserve enough meat sauce for the very top.

Once you lay in the last layer of noodles, spread your remaining meat sauce over the top. Sprinkle on the grated parmesan, and spread the mozzarella slices in a single layer around the dish. If you're using no-boil noodles as per the ingredients, pour in 3/4 cup of cold water around the pan for extra moisture. Cover tightly with foil and bake for 50 minutes.

Pull the lasagne out and remove the foil. Put it back in the oven for 10 to 15 minutes to become golden and get crispy edges. Let the lasagna rest for at least 15 minutes before cutting into it. Top the servings with dollops of the pesto.