Prepare the pasta according to the package instructions.
In a large skillet melt 2 tbsp of butter and add the pork, 1/2 tsp of salt and the fennel seeds. Cook on high heat until the pork is completely cooked. Add the sage and 2 tbsp of butter, mix well and let the meat turn golden brown.
Drain the pasta and place it in the skillet. Mix well and serve with some black pepper and Parmesan cheese.