preparation into 10 simple steps
step 1: Boil water in a big pot and add some salt (if you want).
step 2: Peel the sausage to remove the skin. Chop the sausage to very small pieces (preferably to the stage it looks like minced meat).
step 3: In a smaller pot put some oil and add the chopped sausage and the mushrooms. Fry the mixture into high temperature till they get a golden-brown color.
step 4: Add the tomato puree into the small pot (if you want).
step 5: Add some black pepper (if you want).
step 6: Leave the mixture to simmer at low heat, till the pasta in the other big pot is ready.
step 7: When the water in the big pot is boiling, put the pasta in and leave them for some minutes to boil as instructed on the packet.
step 8: When the pasta is ready, drain them and if you want wash them under cold water.
step 9: Serve the pasta into plates and pour the sauce on top of it.
step 10: Add the parmesan cheese on top of it and serve.