This isn't really carbonara in the truest sense, it's a carbonara inspired leftover-ham-dinner, it was pretty tasty though.
The sauce is dead simple, you just need some kind of cured pork like ham or bacon for the main flavour. I used a few slices from the Christmas ham, which is still good for the moment but is probably on its last legs so it needs using up.
Fry up a little garlic and thinly sliced purple onion with a finely diced red chilli. When soft add in thickly sliced mushrooms and the pork, let them cook through.
Add the juice of half a lemon and a good sized slosh of single cream. Season with lots of black pepper and chopped parsley then serve mixed in with some lovely fresh pasta. Doddle.