Melt the butter with the olive oil in a large heavy-based saucepan over a low heat. Add the onion, celery and carrot and cook for 10 minutes, stirring occasionally, until softened but not coloured. Increase the heat to high, add the thyme, chillies, garlic and meat and cook, stirring, for 30 seconds. Pour in the wine and boil rapidly for 2 minutes, then add the tomatoes and stock and season with salt.
Bring to the boil, then reduce the heat and simmer gently, uncovered, for 30–35 minutes until thickened. Remove from the heat, stir in the parsley, lemon rind and extra virgin olive oil and cover while you cook the pasta.
Cook the pasta in a large saucepan of salted boiling water until al dente: according to the packet instructions for dried pasta or 2 minutes if using fresh pasta. Drain and return to the pan. Toss in the meat sauce, adding more extra virgin olive oil, if needed. Serve immediately with a scattering of grated Parmesan, if liked.