For the polenta bring the water to the boil in a medium sized pan. Pour in the polenta in a slow steady stream, stirring continuously. Bring to a simmer and leave to cook, stirring often, for 20 minutes.
After the polenta has been cooking for about 10 minutes start the sausages. Heat the oilve oil in a deep saute pan, add the sausages and lightly brown.
Add the onion and garlic and cook briefly until soft but not browned. Add the chilli flakes and thyme and cook for 1-2 minutes.
Add the wine and let it bubble for a few seconds, then add the sun dried tomatoes and some salt and pepper. Cover and simmer for 5 minutes.
Uncover the sausages, increase the heat slightly and reduce the cooking juices a little then add the lemon juice, parsley and seasoning to taste.
Stir the butter, parmesan cheese and some salt to taste into the polenta. Spoon it into 4 warmed deep plates then spoon the sausages on top and serve.