Prepare the Pasta: Bring a large pot of salted water to a boil and cook the pasta according to package instructions until al dente. While the pasta is cooking make the Boscaiola Sauce.
Sauté the Pancetta and Mushrooms: In a large fry pan (skillet), heat a drizzle of olive oil over medium heat. Add the diced pancetta and cook until crispy and golden brown, about 5 minutes. Then add the mushrooms, garlic, pepper and half the parsley and cook until they are tender about 5 minutes.
Prepare the Cream. Pour egg and cream into a bowl and whisk until well combined. Turn the heat off then pour cream mixture into the pan with the bacon and mushrooms, stirring gently to combine. (The residual heat will cook the egg through without scrambling it).
Combine the Pasta and Sauce: Use tongs to add the cooked pasta straight from the pot to the pan with the sauce, tossing gently to coat the pasta evenly. If the sauce seems too thick, you can add a splash of the reserved pasta cooking water to loosen it up.
Serve: Garnish with freshly chopped parsley and freshly grated parmesan and serve hot.