When prosciutto, Italian for air-dried rather than smoked ham, isn't available, cook two extra slices of bacon instead. This rich and creamy pasta dish is as good or better than the popular restaurant version.
In a medium saucepan, cook onion in hot butter about 5 minutes or just until tender. Stir in bacon and prosciutto. Cook and stir for 3 minutes more. Carefully add white wine. Bring to boiling; reduce heat. Simmer, uncovered, for 5 minutes, stirring occasionally. Add whipping cream and milk. Bring to a gentle boil.
Gradually add 1 cup of the hot cream mixture to egg yolk, stirring constantly. Add egg yolk mixture to cream mixture in saucepan. Return to a gentle boil; cook and stir for 2 minutes. Add the 2 tablespoons Parmesan cheese and the parsley, stirring just until cheese melts.
Meanwhile, cook the fettuccine according to package directions; drain well. Transfer pasta to a large serving bowl. Pour sauce over hot pasta; toss to coat. If desired, sprinkle pasta with additional Parmesan cheese and cracked black pepper. Makes 4 servings.