Heat oil in the large non-stick frying pan.
Put in the prosciutto and fry for about 2 minsuntil crispyish.
Use a slotted spoon (a large metal spoon with many small holes in it for draining) to remove the prosciutto, letting any fat drain back into the pan. Set aside.
Put in the onion, garlic and herbs in the pan and fry for 3-4 mins.
Spread the chopped onion across the bottom of the pan, then lay the chicken breasts on top of the chopped onion.
Put some pepper on it and fry for 5 mins over amedium heat.
Turn the chicken once, until starting to brown on both sides and the onion is caramelising on the bottom of the pan.
Take the chicken out of the pan; place on a plate until you're ready to use it
Raise the heat under the pan, stir the contents of the pan.
Pour in the wine and let it bubble for 2 mins to reduce slightly (but not much).
Turn the heat down to medium setting.
Return the prosciutto to the pan, stir in the tomatoes (breaking them up with your spoon), also add the tomato purée andmushrooms.
Pour 4 tbsp of water into the empty tomato can, swirl it around, then empty it into the pan.
Cover but allow the steam to escape, and simmer for 15-20 mins or until the sauce hasthickened and reduced slightly.
The chicken should be put back in the pan and cooked, uncovered, for about 15 mins or until the chicken is cooked through and not tough or stringy.
Season and scatter the parsley over the dish to serve with the warm rigatoni or fusilli pasta which place to one side with a little butter and black pepper. Ready to serve.