Begin my making the tomato sauce: heat a saucepan with a good glug of olive oil. Add the onion and cook over a medium heat for 10 minutes or until translucent. Add 1 clove garlic, stir for a few seconds then add the tinned tomatoes. Mix well. Add seasoning to taste, sugar and chilli powder. Bring to the boil then turn down to a simmer. Cook gently, stirring occasionally for about 1 hour.
To make the sausage mix, heat a frying pan with some olive oil and add the skinned sausages. Brown well and break up with a wooden spoon until the sausages break down into sausage mince. Add seasoning and chopped pepper, and cook gently for 20 to 30 minutes.
To the sausage mixture, add the remaining two cloves of garlic, fennel and chilli. Mix well and continue to cook for a further 10 minutes over low heat. Stir in a tablespoon of chopped parsley. Mix well.
Meanwhile, cook the pasta until al dente. Add the tomato sauce to the sausage mix and heat through. Then mix with the drained pasta.
Garnish with more chopped parsley and serve.
Once the sauce is cooked and thickened this can be poured into a bowl and covered and chilled until required.