Heat oil in large deep skillet. Add onion and garlic and stir over low heat until tender. Do not burn the garlic. Add sausage and mushrooms until sausage is cooked through. Stir in the wine and bring to a boil. Reduce heat to simmer and cook until liquid is reduced by half.
While the sauce is cooking down, cook pasta in a large pan of salted water until al dente. Drain and return to pan.
In a large bowl, whisk together the cream, eggs, 1/2 the grated cheese, parsley, salt and pepper to taste. Add to the cooked pasta and then add to the reduced wine & sausage sauce. Toss to mix well and heat through. Serve with additional parmesan cheese and parsley, if desired.