Melt a bit of butter in a pan then add the chopped onion. When the onion becomes clear, add the wine and let it evaporate. Add the sausage, peeled and chopped, the basil and cook for few minutes. Add milk, cream and salt. Cook for about 15 minutes. Cook maccheroni, drain them and pour them in the pan with the sausage sauce. Add pepper and grated parmesan then serve.