In a 10" skillet heat the oil over medium heat for 1 minute. Add the onion and cook for 5 minutes, stirring occasionally. Add the sausage and cook on medium-high, breaking it up as much as possible, till nicely browned.
Add the wine and boil till almost completely evaporated. Add the milk and tomato paste, stirring till blended. It will look weird and grainy but don't worry, it will come together. Once it starts bubbling reduce the heat to low and simmer for 5 minutes. Add salt and pepper to taste.
Meanwhile, cook the pasta according to directions. Drain, return to the pot and pour the sauce over.