Fill a pan with water to cook the pasta, add a good pinch of salt, cover, and bring to the boil.
In a separate saucepan or large frying pan, add the chilli flakes and fennel seeds and cook over a low heat for a few minutes, shaking or stirring almost constantly to prevent burning. Once the fennel smells strong, quickly remove the chilli and fennel from the pan to a bowl or plate and set aside.
In the same pan, heat a tablespoon of oil and add the sausage meat. If using sausages, remove the skins before adding to the pan. Cook over medium-high heat, using a masher or wooden spoon to break into small pieces, somewhere between minced meat and small meatballs. Stir occasionally until lightly browned, around 5 minutes. The sausages will stick to the pan a little, but that’s absolutely fine at this point.
Once lightly browned, add the toasted chilli flakes and fennel seeds to the pan and stir to combine. Cook for another few minutes until the sausage meat is browned, then slowly pour the wine into the pan and keep stirring to deglaze the pan. Decrease the heat to medium-low and continue cooking until the wine has reduced by 2/3.
From adding the wine to the pan, the rest of the cooking process will take around 10 minutes, so plan accordingly so your pasta is ready at the same time. If the sausage mixture is cooked before the pasta, simply remove from the heat and keep warm.
Add the pasta to the pan of boiling water and cook according to packet instructions. Dried pasta is fine, but I much prefer fresh pasta, which also cooks far quicker.
Meanwhile, add the dried oregano to the pan with the sausages and wine, plus the zest and juice of one lemon. Stir and continue cooking on low heat until reduced to an ideal consistency.
Once the pasta is cooked al dente, drain and reserve the cooking water.
Add the cooked pasta to the pan with the sausages and stir well to combine, continuing to cook over the lowest heat.
Quickly add the butter, chopped parsley, parmesan, and a ladleful of the pasta cooking water and keep stirring until well combined and the butter and cheese has melted.
Serve with an additional handful of grated or shaved parmesan, plus a good crack of black pepper.