Heat the oil in a sauté pan or deep frying pan over a medium heat, add the onion and cook for 4–6 minutes until softened but not coloured. Stir in the garlic, fennel seeds and rosemary and cook until fragrant, then remove from the pan to a bowl and set aside. Add the sausagemeat to the pan and fry until it begins to brown, using a wooden spoon to stir and break down the meat. Cook for 3–4 minutes until it begins to go a little crispy round the edges, then return the onion mixture to the pan. Add a splash of white wine and allow to bubble, then stir in the tomatoes and simmer for 10 minutes. Meanwhile, cook the pasta according to the packet instructions until al dente. Once cooked, add the pasta to the sauce and gently stir to coat. Season with a little pepper and serve in warmed pasta bowls, topped with grated pecorino and a few fennel fronds