This is a real winter warmer pasta dish; you need good quality sausages with a high meat content (go to a butcher if you can).
First slit the skins on the sausages and break the sausage meat into little bite sized pieces. Discard the skins.
Heat the olive oil in a good quality deep sided pan and fry the sausage meat pieces over a medium heat until they are browned and crispy all over.
Add the onion and fry on a low heat for about 10 mins until they are cooked through and softened. They should be golden brown.
Next add the garlic and fry for a few minutes being careful not to burn it. Turn the heat up high before adding wine or stock.
Allow this to sizzle on a medium high heat and scrape up any bits of sausage meat stuck to the pan.
Let this bubble away until the liquid has almost completely evaporated, this will take around 10 mins.
Have a large pan of boiling water ready for the pasta. You need about 2 litres of water and about 1 tbls of a good quality salt. When you cook the pasta you want it to be al dente, this will be around 10 mins depending on the make, ,however if you like less bit cook it longer.
To finish add the wholegrain mustard. Season with salt and pepper to taste and the parsley to the pan.
Next add the creme fraiche and simmer gently for a few minutes on a low to medium heat until the sauce has thickened slightly. It should be the consistency of double cream. Taste and check for seasoning one final time.
Drain the pasta and mix well with the sauce. If it is a little thick you can add some of the drained pasta water, this is all down to taste.Serve with plenty grated parmesan.