Put a large pan of salted water on to boil for the pasta. Meanwhile heat the garlic oil in a wok or large flameproof casserole and fry the pancetta cubes over a high heat until bronzed and crisp.
When the water boils and the timing is right add the pasta and cook according to packet instructions until al dente.
Add the butter to the pancetta and when it has melted tip in the chestnuts. Squish them down with a wooden spoon, so that each chestnut crumbles into four pieces, then stir to mix.
Add the marsala and bubble up. Just before you drain the pasta remove about a cup of the cooking liquid and tip about half of it into the pancetta pan. Stir well, bubble and reduce a little.
Drain the pasta well and add it to the sauce, then add almost half the herbs and mix all gently together. Add more pasta cooking water and a little extra butter if you like.