1To make the ragu, heat 2 tablespoons of the olive oil in a large pan over a medium heat and fry the leeks and red peppers for 8-10 minutes until aromatic and lightly coloured, stirring in the garlic, rosemary, fennel seeds and paprika a couple of minutes before the end. Add the mince and cook, stirring frequently and breaking up with a wooden spoon, until it changes colour. Pour in the wine and simmer for 4-5 minutes until reduced by half. Add the passata and stock, and season with salt. Bring to a simmer and cook, stirring occasionally, over a low heat for 45 minutes
2Leave the ragu to stand for a few minutes. Skim off any oil from the surface; discard. Stir in the cherry tomatoes and season. Leave to cool.
Being such a rich buttery meat, there is no need for béchamel sauce – a little crème fraîche finishes it off nicely.
3Using a 30cm x 20cm, 7-8cm deep roasting or baking dish, cover the base with a thin layer of ragu. Arrange a layer of lasagne on top, breaking the sheets to fit. Continue layering until you have about 5 layers of ragu and 4 of pasta, ending with ragu. Dot with the crème fraîche, scatter over the Parmesan, then the peppers.
4When ready to bake, preheat the oven to 200°C, fan 180°C, gas 6. Drizzle over the remaining oil and bake for 50 minutes-1 hour until sizzling – cover with foil halfway. Cook for 15-20 minutes more if cooking from frozen.