Cook pasta following package directions, drain and rinse.
Meanwhile, saute the onion, ham, and mushrooms in butter until onion is tender and mushrooms are golden. Add garlic and cook, stirring, for 1 minute longer. Add the cream, parsley, and pepper. Simmer, stirring occasionally, for about 5 minutes. Taste and add salt, as needed. Toss the sauce with the drained pasta. Serve with more Parmesan cheese.
Serves 6 to 8.