1. Melt the butter in a sauce pan, add chopped Onion and softly cook until golden brown (normally around 3mins)

2. Add chopped rosemary and diced tomatoes and season with salt and pepper and the brown sugar.

3. Cook until the tomatoes have just begun to soften into a sauce, which takes about 5 minutes.

4. Slice the sausage into 5mm/¼in rounds and add to the pan with the crushed chilies.

5. Add the cream and 2 tablespoons of chopped flatleaf parsley, and allow to bubble for 3-4 minutes, stirring frequently until the cream has reduced by half. Remove the pan from the heat and set aside.

6. Cook the pasta until it is 'al dente' (see tips), drain and toss with the sauce, then add the grated parmesan.

7. Toss again, sprinkle with remaining flatleaf parsley, and serve.