Stick a toothpick into each sausage and place in the water. Leave to steep below boiling point for approx. 30 mins. Warm the butter, sauté the leek for approx. 3 mins., season with salt. Add the potatoes and sauté for approx. 3 mins. Pour in the cream and wine, cover and simmer for approx. 15 mins., stirring occasionally. Place the sausages on the leek and potatoes, reduce the heat and simmer for about another 5 mins.