While pasta cooks add olive oil to large sauté pan over medium heat. Add sage leave strips and pancetta if using. Fry a couple of minutes until sage and pancetta strips are crispy but not burnt. Add lemon juice and whisk. Set aside. Partially drain pasta leaving a fair amount of cooking water. Add wet pasta to the sauté pan and return to heat, tossing to coat and thicken sauce. Test for seasoning, adding fresh ground pepper and additional salt if desired. Serve immediately.