Step 1Bring a large pot of salted water to a boil over high heat. Cook the pasta until al dente, about 12 minutes.
Step 2While the pasta cooks, heat the olive oil in a large skillet over medium-high heat. Add the pancetta and cook, stirring, until it starts to brown lightly and begins to crisp, about 5 minutes. Add the onion and continue to cook, stirring frequently, until it has softened slightly, about 3 minutes.
Step 3Add the radicchio and endive, increase the heat to high and continue cooking until they begin to brown, about 4 to 5 minutes. Add the chicken broth, reduce the heat to medium and simmer until the liquid has reduced by a third, about 3 to 4 minutes.
Step 4Drain the pasta and add to the skillet. Stir to combine, then add the butter, cheese and pepper to taste.